Functions and methods

A function is a piece of JavaScript code that is defined once and can be executed multiple times by a program. A function definition looks like this:

function sum(x, y) {



 return x + y;



}

Functions are invoked using the ( ) operator and passing a list of argument values:

var total = sum(1,2);  // Total is now 3

In JavaScript 1.1, you can create functions using the Function( ) constructor:

var sum = new Function("x", "y", "return x+y;");

In JavaScript 1.2 and later, you can define functions using function literal syntax, which makes the Function( ) constructor obsolete:

var sum = function(x,y) { return x+y; }

When a function is assigned to a property of an object, it is called a method of that object. Within the body of a method, the keyword this refers to the object for which the function is a property.

Within the body of a function, the arguments[ ] array contains the complete set of arguments passed to the function. See Function and Arguments in the reference section.

Comment an article   Name   E-mail    Title Available characters: 4000  Notify me of follow-up comments Enter what you see:

No comment posted