Basic PHP Tutorial 4: Variables and Comments

Key Takeaways

hello and welcome to the fourth PHP tutorial in this tutorial we're going to be talking a little bit on comments variables and just a little bit on like string concatenation as it's called but mostly how do you put variables with on into a string basically so with that let's hop right on into it the first thing is commenting there's two ways to comment then you can do a slash slash and that's good for a single line of comments as you can see when you hit Enter and you come down no longer is it the same color and now it's going to throw you some errors whereas it's just a single comment let's just do echo low we'll save that put it back to the server pop over to our old one refresh you see hello but you don't see the this comment here now if you're planning on commenting just like a huge comment or you want to put up like a list like sometimes in tutorials I want to put up a whole different like a whole bunch of examples or defining characteristics for something and you want it you'll just want to be able to list things out without doing slash slash this slash list you know the way to do that to do a multi-line comment is a forward slash star and then wherever you want to end it star forward slash in everything in here is now classified as a comment so we can save that and throw that back to the server refresh and we still have hello so that's comments now I'm gonna go ahead and delete that since wasting space so the next thing is variables so variables are defined in the following way use dollar sign and they can start with any kind of letter uppercase or lowercase and then also you can start with an underscore you can't start with a space and you can't start with a number so if you really wanted to start with some sort of digit you know you can right out to or you can do like underscore to something like that but yeah you just can't start with the digit as you can see it's already getting angry with me so that's how you to find a variable so we're just going to literally call this bar 1 then you use an equal sign and you're basically it's like an assignment operator basically you're assigning something to this variable and what we want to assign the bar 1 is how are you so the way that you can use variables at least in the echo statement is let's say you want to do hello how are you so you want to say hello and then what you'll do is to put it like something to another like to put a variable to concatenate the variable to the string use a period that's called a full stop and then you can just put the variable out now what this is going to do is make somewhat of an ugly addition like in Python you can use either the plus sign or the comm on that common just automatically add to space and the plus sign is not whereas here in PHP you just have the full stop so when we refresh this and we didn't add a semicolon I'm sure yep when we refresh this you'll see the it's kind of jammed together so naturally what you'll have to be used to doing is spacing things so hello and really you want to hear space save that and you'll put that up to the server and you'll refresh and now you see hello space how are you it just looks better and so that's how you add variables and echo out variables naturally as you get further into this with you know using more HTML concepts and stuff it becomes really useful to be echoing out various variables so now just to expand this just slightly further let's say the first variable we want to use is going to be name and we're going to say name is Harrison and we'll do age equals 19 and let's say you want to do you want to echo out hello and you want to build their name and then you want to say your ages and then you want to bold the age you can probably guess sort of how we might do this or a wholly how we might do this but just as a quick example it's good to just kind of run through this stuff so let's say we're going to do this hello and then we want to do the bold the name Harrison but when you spit out a variable you can't you know put unless you put literally the strong tags in front of the variable you could do it that way but instead what we're going to do is just do strong and then we're gonna append name and then again we want to append some more tax you'll have to add this space obviously we already out of the space here and then we wanted to go ahead and close off the strong tag so we just want to bold the name then we wanted to say you are and then again we want the strong tag close that off period age period we already opened up that parentheses early Y quotes there and then we'll just do years for it okay so now it should say hopefully oh we better close off the next strong tag close that off so now it goes hello initiates the strong puts in the name of Harrison space you are initiate strong again and then says the age whatever that is and then years old so we'll save that put that up to the server refresh and sure enough it builds just the name and the age so those are the basics of defining variables doing comments and kind of you know starting to work in variables and to string tags and all of that so as always thanks for watching and until next time