java script call methods from another methods

Question

I'm new in js.

I see code example:

foo.bar().baz()

How described foo bar and baz that we can call so?

Thank you.

Answer 1

What are you are probably after is called chaining. A method can return the object it's running on this, so that another method may be called.

var foo = {
 bar: function() {
 doStuff();
 return this;
 },
 baz: function() {
 doOtherStuff();
 return this;
 }
};
foo.bar().baz();

This is exactly how jQuery works, in order to allow things like:

$('#foo')
 .html('<p>hi</p>')
 .addClass('selected')
 .css('font-size', '24px')
 .show();

• K'': a quick comment for clarification since you said that you are new to JS, this is not a JS feature, you can achieve this in different programming languages by returning an object which has other methods you can invoke
• Alex Wayne: Yep. In fact, wikipedia has example in C#, C++, Java and PHP. en.wikipedia.org/wiki/Method_chaining

Answer 2

So let's say you had an object foo with two methods: bar and bad. The implementation of bar would be like this: function bar() { /* do work */ return this; } That returns foo itself so you can call baz since it's defined in foo.