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JavaScript JavaScript Loops, Arrays and Objects Tracking Multiple Items with Arrays Using For Loops with Arrays

Ryan Schmelter
Ryan Schmelter
9,710 Points
Posted by Ryan Schmelter
Ryan Schmelter
9,710 Points

In this video, does playList take the place of list when the function is called?

I'm confused about why he put -- list -- as the parameter of the printList function. Am I correct to say that in the code -- printList(playList); -- (playList) takes the place of (list) to run the array through the code. If so, why not simply use (playList) as the parameter instead of making a new one?

2 Answers

Annalyn Sarmiento
Annalyn Sarmiento
10,026 Points
Annalyn Sarmiento
Annalyn Sarmiento
10,026 Points 
var playList = [
  'I Did It My Way',
  'Respect',
  'Imagine',
  'Born to Run',
  'Louie Louie',
  'Maybellene'
];

function print(message) {
  document.write(message);
}

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

printList(playList);

In this code, you're correct that list is the parameter of the printList function. When we call the function we pass the array stored in the variable playList into the function.

You could use playList as the parameter in the printList function, but using an arbitrary parameter, like list, allows the function to be reused for other arrays that may be created.

For example, say you create a new array called newList. You would simply have to call the function again, this time passing in the array newList :)

var playList = [
  'I Did It My Way',
  'Respect',
  'Imagine',
  'Born to Run',
  'Louie Louie',
  'Maybellene'
];

var newList = [
  'one',
  'two',
  'three',
  'four',
  'five',
  'six'
];

function print(message) {
  document.write(message);
}

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

printList(playList);
printList(newList);
Alexander Sakaev
Alexander Sakaev
Courses Plus Student 1,757 Points
Alexander Sakaev
Alexander Sakaev
Courses Plus Student 1,757 Points

It is basically can be any name in the parentheses.

function printList ( xxx ) { .....}

Clay Bowser
Clay Bowser
6,619 Points

Wow that's so cool, thanks for the explanation!

edinjusupovic
edinjusupovic
5,664 Points
edinjusupovic
edinjusupovic
5,664 Points

Could you post the code please.