js双向绑定和地址传递带来的痛苦解决方案之对象拷贝

function cloneObj(obj) {
    var newObj = {};
    if (obj instanceof Array) {
        newObj = [];
    }
    for (var key in obj) {
        var val = obj[key];
        newObj[key] = typeof val === 'object' ? cloneObj(val): val;
    }
    return newObj;
};