两个对象深度比较，借鉴，记录

    function deepCompare(x, y) {
        var i, l, leftChain, rightChain;
        function compare2Objects(x, y) {
            var p;
            if (isNaN(x) && isNaN(y) && typeof x === 'number' && typeof y === 'number') {
                return true;
            }
            if (x === y) {
                return true;
            }
            if ((typeof x === 'function' && typeof y === 'function') ||
                (x instanceof Date && y instanceof Date) ||
                (x instanceof RegExp && y instanceof RegExp) ||
                (x instanceof String && y instanceof String) ||
                (x instanceof Number && y instanceof Number)) {
                return x.toString() === y.toString();
            }
            if (!(x instanceof Object && y instanceof Object)) {
                return false;
            }
            if (x.isPrototypeOf(y) || y.isPrototypeOf(x)) {
                return false;
            }
 
            if (x.constructor !== y.constructor) {
                return false;
            }
 
            if (x.prototype !== y.prototype) {
                return false;
            }
 
            if (leftChain.indexOf(x) > -1 || rightChain.indexOf(y) > -1) {
                return false;
            }
 
            for (p in y) {
                if (y.hasOwnProperty(p) !== x.hasOwnProperty(p)) {
                    return false;
                } else if (typeof y[p] !== typeof x[p]) {
                    return false;
                }
            }
 
            for (p in x) {
                if (y.hasOwnProperty(p) !== x.hasOwnProperty(p)) {
                    return false;
                } else if (typeof y[p] !== typeof x[p]) {
                    return false;
                }
 
                switch (typeof(x[p])) {
                    case 'object':
                    case 'function':
 
                        leftChain.push(x);
                        rightChain.push(y);
 
                        if (!compare2Objects(x[p], y[p])) {
                            return false;
                        }
 
                        leftChain.pop();
                        rightChain.pop();
                        break;
 
                    default:
                        if (x[p] !== y[p]) {
                            return false;
                        }
                        break;
                }
            }
 
            return true;
        }
        
        if (arguments.length < 1) { // 这里判断如果没有传值直接返回true
            return true;
        }
 
        for (i = 1, l = arguments.length; i < l; i++) {
            leftChain = []; 
            rightChain = [];
 
            if (!compare2Objects(arguments[0], arguments[i])) {
                return false;
            }
        }
 
        return true;
    }