Some of function in javascript

Apply shares defined variable in functions. Second arguments is first arguments in object functions.

function Person( name,ateru) {
	this.name = name;
       this.ateru = ateru;
}

function sayHello( s ) {
	alert( s + this.name+ '!'+this.ateru);
}

var p = new Person("なんじゃこりゃー！","あてません");
sayHello.apply(p,["電気関係"]);

forEach has one argument. This arguments is callback which has three arguments. It has value,index and target object.

function printElt(element, index) {
    alert('[' + index + '] is ' + element);
}
var a = new Array('a','b','c');
a.forEach(printElt);