You Must Understand Reference Vs Value In JavaScript

Key Takeaways

in this code all we're doing is setting a variable a to 10 and a variable B to high and that just corresponds with the values of 10 and high being stored in memory now if we come in here and we set a variable C to our variable a anytime you do an equals like this all you're doing is taking the value of one variable and setting it to the other so we take the value of a which is 10 and set that to our value for C now if we add 1 to C well we're just going to increment our value by 1. you'll notice it doesn't change anything to do with our a variable now what happens if we deal with arrays though arrays are a bit different in that instead of storing directly our value we're storing a reference to our memory and our memory actually stores our value so as you can see here we have a memory address which stores our value now this means when we modify our C or D we get some interesting things for example if we set D equal to C you remember what we do is we take the value of the variable and set it as the value of the new variable so our value for D is going to be the exact same as our value for C so they both point to the exact same array that means if we add a value to the end of D it's going to add it to the end of our array which is referenced by both C and D so both C and D get that new value the only way we can get around this is if we set D to a brand new array which means D gives its own value