JavaScript allows us make new method available to a specific type. For example, we can augment Function.prototype with a new method like this:

Function.prototype.method = function(name, func){
    this.prototype[name] = func;
    return this;
};

Morever, we can augment a specific type with a new method like this:

Number.method('integer', function(){
    return Math[this < 0 ? 'ceiling' : 'floor'](this);
});

document.writeln((-10/3).integer())

This method help us convert a Number type to integer.