Function

Property Summary

Type	Name	Summary
Function	constructor	Specifies the function that creates an object's prototype..
Number	length	Specifies the number of arguments expected by the function..

Methods Summary

Type	Name	Summary
void	apply()	Applies the method of another object in the context of a different object (the calling object); arguments can be passed as an Array object..
void	bind()	Creates a new function which, when called, itself calls this function in the context of the provided value, with a given sequence of arguments preceding any provided when the new function was called..
void	call()	Calls (executes) a method of another object in the context of a different object (the calling object); arguments can be passed as they are..
String	toString()	Returns a string representing the source code of the function..

Properties Details

constructor

Specifies the function that creates an object's prototype.

Returns Function

Sample

function Tree(name) {
	this.name = name;
}
theTree = new Tree("Redwood");
console.log("theTree.constructor is " + theTree.constructor);

length

Specifies the number of arguments expected by the function.

Returns Number

Sample

function addNumbers(x, y){
	if (addNumbers.length == 2) {
		return (x + y);
	} else
		return 0;
}

Methods Details

apply()

Applies the method of another object in the context of a different object (the calling object); arguments can be passed as an Array object.

Returns void

Sample

function book(name, author) {
	this.name = name;
	this.author = author;
}

function book_with_topic(name, author, topic) {
	this.topic = topic;
	book.apply(this, arguments);
}
book_with_topic.prototype = new book();

var aBook = new book_with_topic("name","author","topic");

bind()

Creates a new function which, when called, itself calls this function in the context of the provided value, with a given sequence of arguments preceding any provided when the new function was called.

Returns void

Sample

var x = 9, 
	module = {
		getX: function() { 
		     return this.x;
		},
		x: 81
	};
//  "module.getX()" called, "module" is "this", "module.x" is returned
module.getX(); // > 81
//  "getX()" called, "this" is global, "x" is returned
getX(); // > 9
//  store a reference with "module" bound as "this"
var boundGetX = getX.bind(module);
//  "boundGetX()" called, "module" is "this" again, "module.x" is returned
boundGetX(); // > 81

call()

Calls (executes) a method of another object in the context of a different object (the calling object); arguments can be passed as they are.

Returns void

Sample

function book(name) {
	this.name = name;
}

function book_with_author(name, author) {
	this.author = author;
	book.call(this, name);
}
book_with_author.prototype = new book();

var aBook = new book_with_author("name","author");

toString()

Returns a string representing the source code of the function. Overrides the Object.toString method.

Returns String

Sample

function printHello() {
	return "Hello";
}
application.output(printHello.toString());