js对象比较

Object.prototype.equals = function(obj) {
        if (this == obj)
            return true;
        if (typeof(obj) == "undefined" || obj == null || typeof(obj) != "object")
            return false;
        var length = 0;
        var length1 = 0;
        for (var ele in this) {
            length++;
        }
        for (var ele in obj) {
            length1++;
        }
        if (length != length1)
            return false;
        if (obj.constructor == this.constructor) {
            for (var ele in this) {
                if (typeof(this[ele]) == "object") {
                    if (!this[ele].equals(obj[ele]))
                        return false;
                } else if (typeof(this[ele]) == "function") {
                    if (!this[ele].toString().equals(obj[ele].toString()))
                        return false;
                } else if (this[ele] != obj[ele])
                    return false;
            }
            return true;
        }
        return false;
    };
    var p1 = {
        name: "jack",
        age: 18
    };
    var p2 = {
        name: "lucy",
        age: 10
    };
    var p3 = {
        name: "jack",
        age: 18
    };
    console.log(p1.equals(p2)); //false 
    console.log(p1.equals(p3)); //true 
    console.log(p1.equals({
        name: "jack",
        age: 18
    })); //true