CODEWITHSUNDEEP
javascript
will
will

Reputation: 3191

Javascript methods from super class

I'm new to javascript, so some of the existing answers on StackOverflow confused me.

If I have a static class inside of a dynamic class (like below). How can I access variables inside the dynamic class?

function ListItem() = {
  var myItem = function() { return "something" };

  ...
  ItemDropdown = function(){
     show : function (){
       //Want to access the ListItem's myItem here
       alert(super.myItem() + "dropdown menu");
     }
  }
}


var foo = new ListItem();
foo.ItemDropdown.show();

Upvotes: 1

Views: 134

Answers (3)

Will
Will

Reputation: 20235

If you want ItemDropdown to be a method of ListItem, you need to declare it using this.

this.ItemDropdown = {

With the way you have myItem defined, you can just call it by itself.

alert(myItem() + "dropdown menu");

You also have a couple syntax errors:

function ListItem() = {
// Should be
function ListItem() {

and 

ItemDropdown = function(){
// Should be
this.ItemDropdown = {

So, you end up with this:

function ListItem() {
  var myItem = function() { return "something" };

  this.ItemDropdown = {
     show : function (){
       alert(myItem() + "dropdown menu");
     }
  }
}

Upvotes: 2

Joe
Joe

Reputation: 82594

use this

function ListItem()  {
  var myItem = function() { return "something" };

  ...
  this.ItemDropdown = {
     show : function (){
       //Want to access the ListItem's myItem here
       alert(myItem() + "dropdown menu"); // no super in javascript
     }
  }
}

I've fixed to errors:

  1. ) ListItem() = {
  2. ) this.ItemDropdown = function () { // then object literal mark up

Upvotes: 0

javamonkey79
javamonkey79

Reputation: 17765

First of all, Javascript is not class based inheritance, it is prototype based inheritance. You need to use terms such as "function constructor". If you are coming from a "traditional" class based inheritance language, then check this out.

This being said, if you want this to work:

var foo = new ListItem();
foo.ItemDropdown.show();

Then ItemDropdown must be a property of the ListItem definition (eg: function constructor) - which means you need to use this.

Upvotes: 1

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