[JS]call, apply method

http://dev-tricks.com/trickscall-and-apply-methods-in-javascript/

by tea4two

JavaScript

var o = { x: 15 };
function f(message1, message2)　　{
    alert(message1 + (this.x * this.x) + message2);
}
	
function g(object, func)　{
    var args = []; // empty array
    // copy all other 'arguments' we want to "pass through"
    // check how many args in g();
    console.log(arguments.length);
    
    // but I want no.3 and no.4 of args
    // which equal to "the value x squared = " and ".Wow!"
    for(var i = 2; i < arguments.length; i++) {
        args.push(arguments[i]);
    }
    //this means f.apply(15, [text1, text2])
    func.apply(object, args);
    //apply's first arguments(object) is invisible
    //defaultly passed to function
}

g(o, f, "The value of x squared = ", ". Wow!");