Java Full Course 2026 | Core Java Tutorial For Beginners | Java Programming Course | Simplilearn

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Hey there, welcome to Simply Learn's Java full course. So, are you ready to dive into the world of programming? Java is one of the most in demand languages right now. And by the time you finish this course, you will have the skills and confidence to call yourself a Java developer. So, why should you choose Java? Well, it's incredibly versatile. It powers everything from mobile apps to massive business systems. Plus, Java's platform independence means your code will run smoothly on almost any operating system, which is pretty awesome. So, in this course, we will walk you through everything from setting up your coding environment to master core concepts like variables, loop, functions, data types, control flow, and even object-oriented programming. But wait, there's more. We will also show you how to integrate AI tools with your Java code, making your development process smarter and faster. And by the end, you will be ready to build real world projects and unlock amazing career opportunities in the booming tech industry. Let's get started. Before we comment, if you want to advance your career as a mer stack developer with a full stack developer course, you can master MongoDB, Express.js, React, NodeJS along with Git, HTML, CSS, and JavaScript to build and deploy interactive applications. In collaboration with IBM, this six-month online boot camp offers hands-on learning through professional projects, advanced AI coding tools and job assist services. So, join us to gain expertise in full stack development and secure your future in tech. The course link is mentioned in the description box below. In today's era, the internet and smartphones have become an integral part of our lives. We use our phones for almost all of our day-to-day tasks. Earlier we used to shop at malls, queue up in front of banks and make our travel bookings at travel agencies. But now we can do all this in the comfort of our homes using smartphones. All of this is possible because of a highle programming language called Java. Hi guys, welcome to this video that will tell you everything you need to know about the class-based object-oriented programming language Java. Java is an object-oriented programming language that is used in a distributed environment on the internet. It is a highle language that is easy to read and understand. Java is popularly used in console, graphical user interface, web and mobile applications, game development and also to make embedded systems. Apart from these, Java is also used to develop software for devices. It is used not only in computers and mobiles but even in electronic devices like televisions, washing machines, air conditioners and so on. Online forms, banking and shopping are possible because of Java. Java is a computer-based programming language invented by James Gosling and Sun Micros Systemystems in 1991. He had a single moto while creating the language. It was write once, run anywhere. This meant that the code would have to be written only once, but it could be used anywhere. They named this language oak because of the oak tree outside Gossling's office. Later, it was named to green, then to Java coffee, which was named after the coffee from Indonesia, and finally to Java in 1995. There are three additions of Java. Each programmer can learn any of these editions based on the application they want to make. Firstly, we have Java Standard Edition. This edition contains core libraries like Java.lang, Java.util, etc. Secondly, we have Java Enterprise Edition. This edition has APIs like JMS, EJB, JSP, Serlets, etc. And lastly, we have Java micro edition which is used to program Java in cell phones, setup boxes, handhelds, and so on. Java is an object-oriented programming language based on C and C++. However, it is improved and simplified to solve the errors in programming. Java files are converted to bit code format using a compiler and then executed by the Java interpreter. The whole Java code is run on the Java virtual machine which provides a runtime environment. Now, the main concepts in Java are its methods and classes. A method is a block of code that performs a task only when it is called. Consider this example. While watching TV, you use the TV remote to change channels. Each button on the remote performs a different task. Methods in Java are the same. We can have methods to add two numbers or email a person or to convert kilometers to meters. A group of methods make a class. Classes are used to organize code just like how fruits, vegetables, and clinical products are divided into different sections in a supermarket. There are a lot of features in Java. Let's start by looking at them one by one. It has a simple syntax and is very easy to understand and learn. Java language is robust. It eliminates errors that occur in the C and C++ languages. Java also has features like garbage collectors and exception handling. This makes Java very unique. The most popular feature of Java is that it is platform independent. Here compilation happens in byte code and because of this Java can run on any machine. It is a very secure language as it contains no virus. Java has a feature of multi-threading. The feature of multi-threading helps Java do multitasking. Java is a portable language as it can run on any platform and data type sizes are set permanently. So, Java program has a fixed size of the code. The last of all, Java is not as fast as C and C++ but provides higher performance than any other language. Now let's see oops concepts in Java. Java has four concepts. Abstraction, encapsulation, inheritance and polymorphism. In Java, we use objects and classes related to the real world that makes the code easier to make and understand. Abstraction means showing the relevant information that is needed for a task. Encapsulation makes the Java code secure. Data is stored within the classes and it is not easy to access the data. The next feature is inheritance. As the name suggests, the attributes and characteristics of one class can be inherited by another class. Because of this, coders take less time to create the code. Lastly, we have polymorphism, which means using the same method for different tasks. In Java, we can use the same object or variable in two different places where their tasks will differ. >> Our first question, who is a Java developer? So Java developer basically is a professional computer software developer who uses Java programming language to build the software. Now Java developer mainly uses Java to build software for desktops, mobile phones and also develop software for similar electronic devices such as a smartphone, tablet, etc. Now to become a Java developer, we need to have at least a bachelor's degree in relevant stream preferably computer science. Later you might want to join an internship or a training exercise that involves a project or some highly recognized certification like Oracle certified Java developer then your dream job in your dream company. So this was a simple walk through or road map to become a Java developer. Now moving ahead we have our main topic for today's discussion that that is the skills required to become a Java developer. Now we shall categorize this into two stages. One is the beginner and the other is the professional. We shall discuss each one of them separately. So first we will start with the beginner. So these will be the basic skills that any interviewer will be expecting out from a pure beginner. So in the beginner section the first skill that we will be discussing is related to the object- oriented programming concepts in Java. So for a beginner the concepts of object-oriented programming in Java play a very important and vital role for an interview. So he or she should be having a strong grip over the object-oriented programming concepts in Java. So followed by object- oriented programming concepts in Java, we have the next important concept in Java which is the file input and output operations and serialization. So serialization is another way of executing your code from a different place. For example, if you write a code and you wanted to execute the same code in a different place in a different computer, all you can do is just serialize your code to that particular system and there the same code will be executed. So followed by the second point, the third important skill we need to have is the good understanding of data structures in Java. Data structures or Java collections are the most crucial parts of programming. So for a beginner it's really important that you have a good grip over all the Java collections. So followed by that the next important skill you require is how to handle exceptions. So exception handling plays a vital role in real time programming. So you better have that. Next after exception handling we have the good understanding of JVM and memory management. So JVM basically is the Java virtual machine. So what happens in Java is you write a code and that particular code is compiled and converted into byte code. So this byte code will be transferred to JVM and then JVM executes your bite code and results in an output. So you need to have the good understanding of JVM and the memory management concepts in Java for a beginner level. So followed by that the next important thing is multi-threading and synchronization in Java. So all those were the basic and important crucial skills required by a beginner if you're attending for an interview because these are the basic skills that every interviewer will be looking out in a beginner. So let's have a quick overview of the skill set again. So for a beginner level the major skill sets that you require are to have a good understanding of object-oriented concepts in Java. Next the file input and operations and serialization concepts in Java. good understanding of data structures or collections in Java, exception handling, JVM or Java virtual machine and memory management and finally multi-threading and synchronization. So these were the major skills that are required by a beginner. Now followed by the skill set we will have another slide that depicts about the ids that you must be comfortable with. So for a beginner these are the basic ideides that you should be comfortable with which are IntelliJ, Eclipse and Net Beans and also these are the mainly used ids in realtime programming as well. So if you are comfortable with these three IDE then it will be an added way to your resumeuming. So followed by the beginner we enter into the next level which is the experience level. So this is really important. So we have multiple skills required by an experience level candidate. So the first one amongst the important skills required by an experienced level candidate are a good knowledge of big data and artificial intelligence. Yes, you heard me right, artificial intelligence. There is a major misconception that R and Python are the only languages that are built for artificial intelligence and data science. But in reality even Java can perform the artificial intelligence, data science and machine learning jobs using the new libraries which are dedicatedly written for the purpose. Now for an advanced or experience level candidate the knowledge of these libraries and the workflow is really important. So followed by that the next important skill required by an experience level candidate is a good understanding of blockchain. Next after the blockchain there are multiple big data frameworks out there which you need to learn. Next after that we have microservices, spring boot and scripting languages such as AngularJS, ReactJS and JavaScript. So let's have a quick overview of the skill set required by an experience level candidate. So those are AI and ML libraries in Java. good understanding of blockchain, Hadoop and big data frameworks, Spring Boot, microservices and finally advanced scripting programming languages like AngularJS, JavaScript and ReactJS. Now these skill sets might look big, complex, complicated and hard to digest. But Java developers are categorized into multiple streams of development. Just for example, we can see Java developers working over web development, Android development, full stack, big data, machine learning, artificial intelligence and many more. Now let us consider three most popular streams where we find Java developers which are the web development areas, Android development areas and finally the fullstack development areas. So first we will discuss the skill set required by a web developer. So for a web developer these are the major skill sets required which are the good knowledge of Java serlet pages or JSP popular markup languages such as XML, HTML and next after that we have model view controller. So one should have a good understanding of model view controller or MVC architecture. Followed by that we have good knowledge of web technologies like CSS and JavaScript and finally Java applets. So the important frameworks for a web developer to be well versed with are Apache Struts play Google web toolkit and finally grails. So these are the popular frameworks that are currently in trend and used by Java web developers. So followed by the web developer next we have is the Android developer. So an Android developer is a software developer who specializes in designing applications for Android marketplace. The Android marketplace is a direct competitor to Apple's app store. This means most of the Android developers job revolves around creating apps that we use on our smartphones and tablets. Now the skill sets required by Android developer are good grip over the Android SDK or software development kit. Next the Android testing. Followed by that a better understanding of Android API and database database connectors like JDBC and Android security and finally get version control. Now get version control will be really helpful to keep your code updated. Now followed by the skills required by an Android developer. We will go through some important frameworks and user interface development software tools required by an Android developer in real time. First let us discuss the user interface development tools like Flutter and ReactJS which are the most popular ones amongst the others. So ReactJS is an open-source front-end JavaScript library for building user interfaces or UI components. It is maintained by Facebook and a community of individual developers and companies. React can be used as a base in the development of single page or mobile applications. So next after ReactJS we have the Flutter. Flutter is an open-source user interface software development kit created by Google. It is used to develop applications for Android, iOS, Linux, Mac, Windows, Google, and many more from a single codebase. So, next we have the Solar 2D. Solar 2D is a free and open-source cross-platform software development kit. And then we have the Android Studio. That is another popular development kit just for Android. Now, next in the docket is the Java fullstack developer. A full stack web developer is a person who can develop both client and server software. In addition to mastering HTML and CSS, he or she also knows how to program a browser like using JavaScript, jQuery, Angular and Vue. So now the major skill sets required by a fullstack developer are having a good understanding of software design and architecture, understanding of DevOps, knowledge of microservices, APIs and libraries, design patterns in Java, React and Angular, scripting languages and finally should be capable to work on front end and back end. So these were the major skills required by a fullstack developer. So followed by this we shall also discuss the major frameworks required by a fullstack developer. So these are the major tools, frameworks and scripting languages that are supposed to be known by a fullstack developer. We have the integration tools such as genkin and devops related tools like kubernates and docker and scripting languages like angular and react and frameworks like spring and testing tools like junit. So with this we will move ahead into our next important topic that is the roles and responsibilities of a Java developer. So first we will discuss the roles and responsibilities of a Java developer at beginner level. So the important roles and responsibilities for a beginner are to be able to define the objectives by analyzing the requirements of the clients. Followed by that to be capable enough to complete the assigned job before the deadlines, design and test basic codes, resolve the reported issues in time and troubleshoot the code. Improvise the existing code quality and finally support the user with proper documentation of the code. So these were the important responsibilities of a Java developer at beginner level. Now let us advance to the next level where we will discuss the roles and responsibilities of experience level candidates. So the roles and responsibilities of an advanced level or experience level candidate are all the basic responsibilities of a beginner. So followed by the basic responsibilities, an advanced level Java programmer should be having a thorough knowledge of system functionality and features. Followed by that, the experience level Java programmer should be able to design and develop user interface, enhance the reputation of the company, recommend updates based on the performance, ensure the best possible responsiveness, and finally explore and add value to the achievements of fellow co-workers. So these were the important roles and responsibilities of a Java developer both at beginner level and experience level. Now let us check out the companies which are looking for Java developers. There are many companies that are looking for Java developers in the current IT industry. Some of the major MNC's looking out for Java developers in the current IT industry are Cognizant Inforces, Oracle, Capgeemini, Dell, Amazon, Vipro, Emphasis and Accenture. Now that we have discussed the companies hiring Java developers, let us take a step further and discuss the salary trends of the Java developers in the current IT industries. Now let us discuss the salary trends of Java developers in India first. So the salary trends for a Java developer who is going through the beginner level or an internship level start from 2 lakh to 4 lakh rupees perom. Similarly for an experience level Java developer the salary trends start from five lakh and go up to 10 lakhs and above based on your experience level and skill set. Now let us go ahead and discuss the next country which is the United States of America. So for a Java developer at beginner level, America offers $55,000 to $80,000 perom. Similarly for an experienced level candidate, America offers $85,000 to $125,000 perom based on the experience and skill set. Now finally we have the United Kingdom. The United Kingdom offers £45,000 to £60,000 for a Java developer at a beginner level. And similarly for an experienced level Java developer, United Kingdom offers £65,000 to £85,000 perom. So these were the salary trends of Java developers in multiple countries. So if you wish to join the right training exercise that covers the complete skill set according to the standards of top MNC's created and explained in a detailed manner by realtime industry experts then simply learn would be the right choice. If you visit the simply learn official website for Java related training then you can find the simply learn has beautifully organized all the major topics of Java in a resultoriented manner that will be helpful for both beginners and professionals. So the key features of Java training offered by simply learn will have 70 hours of blended training, hands-on coding and implementation of two web-based projects. It also includes hibernate and spring frameworks, 35 coding related exercises on core Java and lifetime access of self-paced training and finally the flexibility to choose your own classes. So the benefits of Java certification training offered by simply learn will have the following. You can achieve your designation of becoming an Java architect, Java developer, database administrator or web developer with the certification from simply learn on Java. So the average salaries for a Java developer with certification will be varying from 16 lakhs as minimum and will also reach up to the maximum of 27 lakhs perom. The Java certification from SimplyLearn has been recognized by multiple multinational companies. And some of the major MNC companies that are hiring Java developers with the certification of Java are Wells Fargo, Oracle, Accenture, City Bank and many more. Now we have the three varieties of training options which are self-paced learning, online boot camp and corporate training. >> So what is Java? It is a fast, reliable and secure programming language that can be used in several websites and applications. It can be used to create applications in a single computer or one that could be distributed across several servers and clients. Java can be used in several scenarios independent of the system that it is used on. So let's look into what Java Development Kit means. All the Java applications and applets are developed using the Java development kit that is JDK. Now the JDK consists of the Java runtime environment, an interpreter, a compiler, an archiver and a document generator and a few more tools that go into developing a Java program. So now let us have a look at the components of JDK. Java runtime environment JRE primarily is a part of JDK and it can also be termed as Java RTE. The JDK provides the minimal amount of requirements needed to write and compile a Java program. JRE consists of the JVM supporting files and the core classes. The JVM is key to both JDK and the JRE because it is embedded into them. Now, whichever Java program is being run, the JVM is that component of Java that executes a program line by line, thus giving itself the work of an interpreter. We are now in a position to deep dive into the process with which JDK, JRE and JVM work. Let's take a source file and save it with the extension Java. This file is compiled and converted into a set of byte code which changes the file extension into class. This is done specifically by the JDK. Now here are the steps that follow. Class loader. It makes sure that all the necessary classes are loaded in the time of the execution of a program. Next byte code verifier that is JVM. The byte code verifier checks the code for errors or irregularities based on access rights on objects or implementation of pointers. It makes sure that the code fulfills the specifications of JVM and does not break the system integrity. And finally interpreter which is JVM. Now while running the program the interpreter loads, checks and runs the code. The implementation is made by the JRE which is the final process. The latest release is JDK9 and it was released in October 2017. But it was in JDK8 that a new feature called the Java lambda expression was introduced that changed the face of Java. Now Java lambda expression is a kind of function which does not need any class to be created. It has been included in the latest version of JDK as it provides a clear concise way to pass functions around. This also replaces earlier bulky anonymous classes and reduces code verbosity that is the length of the code. The syntax for the lambda expression is this argument list arrow token body. Now the syntax consists of three components which are argument list. This can be empty or non-mpt. Next the arrow token. Now this is used to link argument to body and finally body. This contains the statement that works with the function. Let us now just see an example of using lambda expression and contrasting it with how code would have been written with anonymous classes. This is the old method and this is the new method with lambda expression. Just have a look at how lambda expression syntax has been used over here. The JDK9 has been released recently and it seems promising with respect to new features and abilities. Here are some of the features. The first one is Java platform module system. This module allows strong encapsulation and declare explicit dependencies. Next, JShell. With the help of JShell, one can directly start writing the code on the console and execute them. Improve Java doc. Java docs have got the search right in the API documentation and as an added bonus the output is also compliant to HTML 5. Next, stream API. The stream API also introduced in Java 8 allows programmers to easily parallelize code for improved concurrency and introduces functional programming abilities to the language. The stream API in conjunction with lambda expressions also comes in handy while iterating, filtering and extracting large amount of data. The release of multi jar makes it possible for quotes to be run on the newer versions of JDK to be released. >> So how does algorithm work in real life? So we'll have a use case here on my screen. We have a lady and she is Shrea. Shrea wants to make some tea and for that she's following some steps. So the first step is she'll take a pan and fill it with water and place it on a gas tub. Followed by that the second step is she'll make sure that the water comes to a nice boil and then she adds some tea leaves and sugar. Followed by step two we have step three where she'll allow the leaf to be fully expanded and she'll add some milk after that. Next, we have the step four where she will wait for the tea to come for a good decent boil. Next, we have step five where she'll turn off the gas and she'll take the pan off from the stub and the tea is ready to get filtered. And lastly, we have the step six where she's all set with the tea. So, in computer science, an algorithm is a method or set of rules that we must be following to perform some specific calculations or other problems solving operations. As a result, an algorithm is a collection of rules or instructions that govern how a work needs to be conducted step by step to achieve the desired results. To accomplish a task, we first provide some input and then follow a sequence of steps to acquire the required outcome of the input. So that is the fundamental definition of an algorithm and we also had a use case and now we will move ahead and understand the characteristics of algorithms. So basically we have six characteristics of algorithm. So the first one is it should be clear and unambiguous. The second one is that it has to be well-defined inputs and the third one is that it has to be having well-defined outputs as well. The fourth property of an algorithm is its feasibility. Followed by that finitness and finally we have language independence. Now we will look into each one of the characteristics in detail. So first we have clear and unambiguous. So this statement is the one which states that the algorithm should be straightforward, simple and easily readable. Each one of its steps should be distinct in every way and lead it to a single conclusion. So the next one is it should be having well-defined inputs. So this means that an algorithm should indicate what output can be expected as well as the input should be properly well- definfined. Now we have the third one. Similarly, we should also have well-defined outputs. So the well- definfined output characteristics of an algorithm means that the algorithm must clearly indicate what output can be expected as well as the output should also be well defined. Followed by the third characteristic we have the fourth characteristic that is the finitness of algorithm. So the finitness of algorithm says that the algorithm must be finite and it must not result in infinite loops or similar situations. So followed by the fourth one we have the fifth characteristic that defines about the feasibility of an algorithm. So feasibility of an algorithm states that the algorithm must be really simple, generic and practical. It must be able to be executed with resources available. Now the last characteristic of the algorithm is being independent of the language. So it means that the algorithm should be defined in such a way that it is completely independent of the language. It must be simple instructions that can be implemented using any programming language. So these were the six major characteristics of algorithm. Now let's move ahead and understand how to write an algorithm. Writing an algorithm does not have any hard and fast rules. Next, algorithms are never created to support a specific programming language. As we all know, algorithms should be capable enough to support the conditional statements such as if, if, else, switch, etc. An algorithm should be capable enough to execute some of the conditional statements such as if, if, else, switch, etc. And also, it must be capable to execute the iterative statements such as for loop, while loop, do loop, etc. We usually create algorithms in a step-by-step manner. However, this isn't always the case. After the problem domain has been well defined, algorithm writing is a procedure that is carried out. We build an algorithm to find a solution to a problem. A problem can be resolved in a variety of ways. Let's look at an example of how to write an algorithm. Consider the following scenario. We need to create an algorithm to determine the largest number among the three given numbers x, y, and z. As a result, the initial solution to the problem can be written in this manner. So, we begin with reading all the three numbers. And in the second step we will have a condition that says if x is greater than y we will proceed to step four. Else we will proceed to step five. Next in step four we establish a condition that if x is greater than zed then x is the largest of the three numbers. Otherwise zed is the largest. If y is greater than zed zed will be the greatest number otherwise y will be the largest number amongst all the three in step five. and the procedure will be terminated. Let's have a look at what the next solution has to offer. In this algorithm, we begin by reading all the three variables. Then compare all the three numbers in the third step to determine the largest number which is if x is greater than y then there is another if else statement that states that if x is greater than y then x is largest otherwise zed is the largest. Then there's if else statement which says that if y is greater than zed then y is greater otherwise zed is the greatest of the three numbers. So this is how we have multiple solutions to the same problem. So after discussing these solutions we will move ahead and understand algorithm analysis. The algorithm may be studied in two levels. First before it is made and then after it is created. The two analysis of an algorithm are as follows. The first one is priority analysis and the second one is the post analysis. So first we will talk about the priority analysis. Priority analysis refers to the theoretical analysis of an algorithm performed before its implementation. Before implementing the algorithm, other parameters such as processor speed might be considered which does not affect the implementation component. Next we will talk about post analysis. A practical analysis of an algorithm is called as posterior analysis and it utilizes any computer language to build the algorithm. The purpose of this analysis is to determine how much time and space the algorithm takes to operate. Now after being understood the algorithm analysis we will be able to comprehend the algorithm complexity. Two methods can be used to assess the algorithm complexity. The first one is time complexity which states that the amount of time required to finish an algorithm's execution is known as its time complexity. Followed by time complexity. The other one is the space complexity which is calculated by the quantity of space required to solve a problem and produce an output of space complexity of an algorithm. Let's take a closer look at these complexities. Now we will begin with time complexity of an algorithm. The big O notation is used to express an algorithm's time complexity. The asytomatic notation is used to depict temporal complexity of big O notation. The time complexity is mainly determined by counting the number of steps required to complete the task. Let's take a look at an example to understand this time complexity in a much better way. If we want to find out a multiplication of n numbers, we can do it by executing a loop from 1 to n. Then calculating multiplication when the loop ends. Then multiplication holds the n numbers multiplication. And last we return the calculated multiplication. The loop statement's time complexity will be at least n. And when the number of n increases, the time complexity will also increase. While the code's complexity that is returns multiplication will remain constant because its value is unaffected by the value of n and it will obtain the result in every single step. Next we will discuss about space complexity which is expressed with big O notation just as time complexity. These four items are stored in space complexity. It initially saves program instructions, then stores constant values, then stores variable values, and finally it keeps track of function cells, jumping statements, and so on. The sum of auxiliary space and input size is used to calculate space complexity. The extra space or temporary space used by an algorithm is referred to an auxiliary space. After learning about algorithm complexity, we will look at some of the algorithms pros and cons. So let's start with the advantages of algorithms. Firstly, algorithms are easy to understand. Next, algorithms are step-by-step representation of a solution. And lastly, the problem is broken down into smaller bits or steps in an algorithm making it easier for the programmer. Now, an algorithm also have various drawbacks. One of which being it takes long time to write hence it is time consuming. Second con of the algorithm is algorithms make it harder to demonstrate branching and looping statements. So followed by the advantages and disadvantages of algorithms. We now enter into the final segment where we discuss the differences between algorithms and programming. So the first difference is that an algorithm is a type of programming. On the other hand, a program is more directly associated with the computer performing one or more tasks. But an algorithm is more of a notation, a technique for solving a problem. Now let us discuss the second difference. An algorithm can be decoded or run by a human whereas the program is only run or decoded by a set of compilers of the computer. Now the third difference basically an algorithm is a design of the solution to the problem. Here we can only analyze the solution but we can never run it. But whereas on the other hand programming is completely a different ball game. Here you can directly implement a certain phase or an entire program and test the programs and get an output. So the fourth and the last difference between an algorithm and programming is an algorithm is written using natural human vocabulary. Whereas programs are written using any programming language such as C, C++, Java, Python, etc. And welcome to this video where we'll be telling you how you can install Java on your Windows 10 operating system. After we're done with this installation, we'll also show you how you can run a very simple program. So now let's get started. So now let's download Java. Let's go to Google and search for Java download. We'll go to the link we see here, oracle.com. So now here we have the web page. Here we can see Java SE13. So this is version 13. But this isn't the one we are going to download. We're going to download the ETH version, version 8, which is here. Now, we're doing this because 8 is one of the more commonly used versions of Java. So let's click this. And here we'll go down. We need to accept the license agreement before we can download it. Now, we have two versions here, x86 and x64. Now, you can download it depending on what version your operating system is. Now, if you do have a Windows 10 operating system, it's highly likely you have a 64-bit version of Windows. Now, if you do have a 32-bit version of Windows, you can take the x86. So, let's download this. So, we've actually already logged in. So, we just need to run the installer file now. Let's go to downloads and run the file. So here we have the installer. We'll go to the next step. We'll select this to next. Here we can see where the file is being installed to. We'll go to next. Now if you want to change where you want to install Java, we can press the change option. I'm just going to keep it here. We'll press next and let's commence with installation. And there we go. The installation is now complete. So we don't need any tutorials or API documentation. So we'll just finish off and go to close. Now to see if Java is installed in your system, we can go to command prompt and type the term Java C which refers to the Java compiler. Now as you can see here, this shows a number of different options you can choose from. This also indicates that Java has been successfully installed in your system. Now, if the installation was not successful, you'll see something like Java C is not recognized as an internal or external command, operable program or batch file. But since we've done it successfully, this is what will be shown now. And now we're going to set an environment variable. Now, what exactly is an environment variable? Now, assume you have a file which has a Java extension. This environment variable tells the computer that the Java program needs to be called to run this particular file. So to set the environment variable, we'll need to go to control panel here. Go into system and security, go to system and select advanced system settings. And then this shows up. Now before we go into environment variables, we'll need to go to where the Java file was installed. So let's go to this PC C drive program files and here let's go to Java. So let's go to JDK which is the Java development kit. Let's go to bin here and copy this path. We'll go back to environment variables. Select path here and then press on new. Paste this and okay. Now we'll go back and go to JRE to the path of JRE which is Java runtime environment. You click on this pin again and copy this path. Select this one. New and paste that. And there we go. The environment variables are now set. Now let's talk about running that simple program I told you about. Now this is possible with the help of an IDE. An IDE or integrated development environment will give us a platform to code Java. We will be using Eclipse and Intelligj as they are popular and commonly used. That being said, there are several other IDEs that are available in the market. So now let's work with Eclipse. Let's go to Google and search for Eclipse. We'll go to this link. Press download. And then this shows up. Let's click on download. Now we've already downloaded the software. So I'm just going to directly go into the install phase downloads and select Eclipse. With this you can see that there are multiple options for you to choose from. So we're going to select Eclipse IDE for Java developers. Now you have other options like for C and C++, JavaScript, PHP and so on. Let's go to the first one. And here you have the details. You can change them if you want. But I'm just going to go ahead with installation. Now press accept. Now here we remember accepted licenses and press accept. And then here as well we'll remember accepted certificates. Select this one and accept selected. And there you go. The installation is now complete. Let's click on launch now. So here we are setting up a directory as a workspace. Uh I'm not changing it here. So I'm just going to go with launch. Here we have the Eclipse workspace. Now let's close this first. And here we have the package explorer. Now in case this doesn't show up, you can go to window show view and select on package explorer. So now let's go to file new and java project. We need to set up a project name. I'm going to call it my project one. Go to next. We'll go to source. So this is where the source code for your program is going to be stored. Then let's finish. And now we'll click on my project one. Go to source. I click new and create a class. We'll claim I'll name the class my class and create it. And here we have it. So now let's write a simple program to multiply two numbers. So now let's write the main function. open bracket. Now we're going to initialize the first number. Now the second one and finally the output and finally the variable that will store the output. Now we'll just give them a simple print statement. Now let's run the code by clicking this option here using my cluster Java. And there we have it. Here the product is shown to be 100 indicating that the program is running successfully. Now we're done with Eclipse. Now let's move on to the other ID I was talking about which is Intelligj. So for that again we'll have to go back to Google so that we can download it. Search for IntelliJ download. Go to this link here. So here you can see that we have two options. The ultimate edition and the community version. Now here the ultimate version has way more options as you can see here. But it's a paid version and only has a free trial. Now the community version is free. So that's what we're going to take. So we'll click on download here. So I've already downloaded the software so I don't need to do it again. So I'm going to go downloads and so here we go. Let's just click on next. Select the location where you want to install it. Press next. Now we will add a 64-bit launcher shortcut on the desktop and create associations. So basically this means that these are the different file extensions that this will support. So Java.groovy. And now let's go to the next step. We'll install now and we'll wait. And there we go. The installation is now complete. Let's not import any settings. We'll accept the privacy policy. We'll set defaults. Now let's create a new project. So here, make sure your project SDK is set to the version of Java you've installed. Make sure this isn't blank. We'll go to next. Here you need to select this option which is the create project from template. And we are now going to create a command line application. Press next. Name the project which I'm going to call my project two. You can change the location if you want. I'm just going to keep it the way it is. And then click on finish. So now we're going to create a simple program through which based on the user's input we can determine whether a number is even or odd. So first we're going to import the package scanner through which we can take the user's input. Next let's go inside here. Let's create the variables reader. Now let's ask for the user's input. Enter a number. We're taking in the value now in the variable num reader dot next int. So this is with which we'll be taking in the value from the user. So we're going to set up a condition to determine whether the number is even or not. So if the number when when divided by two provides the remainder zero, it indicates that it's an even number. We'll show them then Now for the else case, the number is not even or in this case odd. There we go. We're done. So let's run this program. So let's enter 12. The number is even. And there we go. We have a successful output. This indicates that the program is running successfully. So first of all, understand why do we need loop statements. So generally whenever you are dealing with some data structures in Java which can store multiple elements. For example, we saw array which can store multiple elements. String is also basically technically a character array which is storing multiple characters. So whenever you have these kind of data structures where you have multiple elements being stored in the same uh then in that case you would like to have a way to iterate or access all of the elements in a seamless fashion. One of the ways is to access them individually one by one. But that's too much of work. That's too much of code. There has to be a simpler way of accessing all the elements one by one if I want to and that's where the majority of the use cases for using loops coming to picture. Now Java provides multiple constructs to write loops in Java. There is a while loop, there is a dowhile loop, there is a for loop, there is also an enhanced for loop. And in the previous versions of Java, a use case of iterator was also very popular. So there are multiple ways in which you can actually iterate over a collection and access all the elements of the collection one by one and you can use it to multiple useful cases. For example, if you have a huge array of employee salary and you want to give bonus to each of the employees and add the bonus to the salary then you need to do this addition for all the employees. It would be nice to have to return a while loop and the while loop can automatically access all the employee salary one by one and keep adding the bonus to the salary. This would be an easier way to do this rather than individually updating each employee salary. And the first loop statement we are going to understand is a while loop. So the syntax of while loop is very straightforward. You write the while keyword. You enter the actual condition which will be evaluating to a boolean true or false. So you write the expression which will be a boolean expression exactly similar to the conditions which you used to write in your if statements. So you write your condition which will evaluate to either true or false and then you write your statement and these statements will keep executing till the time this particular expression evaluates to true. So generally the way it works is that it will enter the while block it will evaluate the expression. If the expression becomes true then the statements inside this particular while block will be executed and after the execution of the statement it will again go back again evaluate the expression. We call them steps basically. So it will go to the next step again evaluate the expression. If this again if this still holds true it will again go inside execute the statement move on to the next step. it will again go to the evaluation. So this this loop will continue to go till the time this condition will hold true. If it still doesn't make sense for you, don't worry. We will have a demo of it to make you understand how to use the while loops. And maybe it's a good idea to switch to the IDE and look at an example of it. So I have already created while demo for it. Here it is. It looks very small and simple but it will get to the point where we can understand how and why we'll be will we be using the while loops. So I've created a while demo class. I've added a public static void main method here which is the entry point. I have declared a variable which is int count equal to 1. So the count value is one right now. And then I'm writing a condition here. I'm saying while count is less than 10 do this. So it will print the current value of count and after that I'm using the post increment unary operator. If you remember we covered this in the previous sessions. What is the meaning of this? It basically will increment the value of count by one. This expression is is equivalent to if I write it in this way. If I write count equal to count + 1. This is exactly the same as this. No difference. So this will have the same impact. I will just remove this line because we already have the count ++ here. So if we try to understand this, we are basically incrementing the count and then checking the condition again. So at first time it will be 1 less than 10. Yes, that is true. It will go inside and print the count value, the current count value which will be 1. And then it does count ++. So now the count value becomes two. It will again go back here again check the condition saying is 2 less than 10? Yes, that is true. So the while condition again becomes true. It will again go inside this. Print the current value of count which is two. Then do count ++. So it will again increment the value of count. So the now the count value becomes three. Again go back here at condition and saying is three less than 10. Yes, that is still true. Again come here print the three. Again go here make count as four. Four less than 10 prints four. Again count ++ count becomes five and so on so forth. It will keep doing that till the value becomes 10. So at a step when count++ results in the count value being updated to 10, it will go here and say is 10 less than 10. Now that is not true because 10 is equal to 10 but 10 is not less than 10. So this condition will become false and it will exit of this while loop and it will come here and it will execute if there's if there was anything written after the while loop that will be executed. So that's the idea that you want to do something till a particular condition holds true. Then you can use the while loop define your condition and execute the statements and try to do something which changes the state of this condition. Here I'm changing the count so that every time a new evaluation happens. If I comment this, this will result in an infinite loop because one will always be less than 10. I will not be incrementing the count here and it will keep running forever. it will never stop. It will just keep printing one one every time till your computer program runs out of the memory. So always remember not to end up into an infinite loop. That's probably one of the biggest mistakes any beginner programmer does. So please try to be aware of that particular uh loophole. Not try to run an infinite loop. Always try to write something in the code block which can change