Methods to check Array, Function, or RegExp

util.js

function isArray(value){
    return Object.prototype.toString().call(value) == '[Object Array]';
}

function isFunction(value) {
    return Object.prototype.toString().call(value) == '[Object Function]';
}

function isRegExp(value) {
    return Object.prototype.toString().call(value) == '[Object RegExp]';
}