Are variables defined in the parameters of the function?

Hello there, i was struggling as well understanding this and i still do it`s okay . You got some great replies from the Treehouse community already. My way of approaching this issue was to think of like this:

function printList ( list ) <== // The list here does not have any value yet it`s like an undefined variable ) {

let listHTML = '<ol>'; for ( let i = 0; i < list.length; i += 1 ) { listHTML += '<li>' + list[i] + '</li>'; } listHTML += '</ol>'; print( listHTML ); }

printList( playList ); <== // Here the value of the list is whats stored into the variable of the playList.) // We could have called the parameter ( list ) a different name it does not matter as long as you assign the value of the playList. Ive changed it to the name of 'dog' and it works the same. You can take a lot here : ``` javascript

function printList( dog ) { let listHTML = '<ol>'; for ( let i = 0; i < dog.length; i += 1 ) { listHTML += '<li>' + dog[i] + '</li>'; } listHTML += '</ol>'; print( listHTML ); }

printList( playList );

Ps: I tried to make it really simple, i apologise if i maybe confused you more but this is really what helped me understand this.

Parameters are declared when they are named in the function definition. For example:

function print(message) {  // <-- this declares "message" for use inside the function body

If a previously declared variable by the name "message" exists, the parameter will "shadow" it (make it not accessible) inside the function.

Hey Trajce! I agree with my friend Steven.

In the parameters of a function you state the name of a variable that you will use in the rest of your function.

function print(message) {}

But this variable is not supposed to be defined earlier in the code. This variable is defined when you call the function:

print("Hello World!");

I hope this helps you out!

Hi, You can define a variable outside the function first but that variable will be in the global scope and other functions can access and change that too. e.g you can write your code like that

var message = "Hello, there"; function print( ) {document.write(message);} print();

In this situation, you don't need to declare the parameter because parameters are in the scope of the function and only that particular function can access and change that variable. so if you want to share the variable among different functions place it in the global scope like this code otherwise use it as a parameter.