详解JS数据类型的值拷贝函数（深拷贝）

function mottoClone (obj) {
 if (obj === null || typeof obj !== 'object') return obj;
 if (obj instanceof Boolean) return new Boolean(obj.valueOf());
 if (obj instanceof Number) return new Number(obj.valueOf());
 if (obj instanceof String) return new String(obj.valueOf());
 if (obj instanceof RegExp) return new RegExp(obj.valueOf());
 if (obj instanceof Date) return new Date(obj.valueOf());
 var cpObj = obj instanceof Array ? [] : {};
 for (var key in obj) cpObj[key] = myClone(obj[key]);
 return cpObj;
}

支持的数据类型或格式有：Boolean,Number,String,RegExp,Date,Function,Array,JSON

支持深拷贝（循环迭代），如：

var obj = {
 id: 1,
 name: 'xxx',
 sayName: function () {
  console.log('my name is' + this.name);
 },
 childs: [
  {}, 
  {}, 
  ...
 ],
 opts: {
  xxx: [],
  ...
 },
 ...
};
var newObj = mottoClone(obj);