Microsoft® JScript™ Function Object

Language Reference  Version 2

See Also                    Methods                    Properties

Description

Prototype for a function

Syntax 1 (see function Statement)

function functionname( [argname1 [, ... argnameN]] ) {
    body
}

Syntax 2

var functionname = new Function( [argname1, [... argnameN,]] body );

The Function object syntax has these parts:

Part	Description
functionname	The name of the newly created function
argname1...argnameN	An optional list of arguments that the function accepts.
body	A string that contains the block of JScript code to be executed when the function is called.

Remarks

Syntax 1 is the standard way to create new functions in JScript. Syntax 2 is an alternative form used to create function objects explicitly.

The function is a basic data type in JScript. Syntax 1 creates a function value that JScript converts into a Function object when necessary. JScript converts Function objects created by Syntax 2 into function values at the time the function is called.

For example, if you want to create a function that adds the two arguments passed to it, you can do it in either of two ways:

Example 1

function add(x, y)
{
   return x + y;
}

Example 2

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

In either case, you call the function with a line of code similar to the following:

add(2, 3);

Example 3

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

var funcName = function(){} is just another way to write function funcName(){} The first is more flexible than the second. It allows you to assign a function to a variable or property just like a string, number, or other kind of object. The second only allows you to create the function within the current context, while the first allows you to do something like this: myObj.funcName = function(){} The following is not valid: function myObj.funcName(){}

See also:

• http://helephant.com/2008/08/javascript-anonymous-functions/

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