Assigning a function to a variable in JavaScript

Question

function abc(){
    //multiple variables and functions
    a:function(){alert("a")};
}
function test(){
    var k=abc();
    k.a();
}

In the above case, I have a huge function abc() to be assigned to a variable. I want to call the member functions that are visible, like a() from the variable. Is this possible to implement and please give me a sample code if so.

Answer 1

When you include the parenthesis after your function, you're assigning the result of the function to your variable.

If you want to assign the function itself, just omit the parenthesis:

var k = abc;
k.a();

EDIT

Per @Kuba Wyrostek's answer, and @Pointy's comment, that a() function won't be properly exposed.

You'll need to take a look at the Module Pattern . What you need to do is to assign a function to a variable, and have that function return the functions that you want to be able to use outside of that function. This helps with encapsulation .

It's a little hard to tell from your code in the comment exactly what is the user-generated code, but I'll do my best.

var abc = (function () {
    var grabApi,
        initialize;

    // Just an example of how to assign an existing function
    // to a property that will be exposed.
    grabApi = SCORM2004_GrabAPI();

    // This is an example of how to have a property that will be
    // exposed be a custom function passing a parameter.
    initialize = function(initString) {
        return SCORM2004_GrabAPI().Initialize(initString);
    };

    return {
        getApi: grabApi,
        init: initialize
    }
}());

You can then use this abc object like this throughout your code. Again, this is trying to give an example of how to do what I think you're trying to do based on your comment.

// Assign the SCORM2004_GrabAPI function to a variable.
var SCORM2004_objAPI = abc.getApi();

// Call the Initialize function with an empty string.
abc.init("");

Answer 2

Hmmm… contrary to @krillgar's answer, I believe you were expecting your abc() to return new object. Something like this:

function abc(){
    var privateVar;
    return {
    //multiple variables and functions
    a:function(){alert("a")}
    }
}
function test(){
    var k=abc();
    k.a();
}

Answer 3

You should make it an object. In this way you can access its property a .

var abc ={
    a:function(){alert("a")}
}
function test(){
    var k=abc;//Ofcrse remove the parenthesis 
    k.a();
}
test();