现在有一个对象
var obj = { ???name: ‘隔壁老王‘, ???age: 60, ???sex: ‘male‘ ???}我们现在想把obj里的每一个属性拷贝到一个空对象var obj1 = {}中，那么需要写一个克隆方法，首先遍历一下obj对象，然后把里面的每一个属性都拷贝过去。代码如下：
var obj = { ???name: ‘隔壁老王‘, ???age: 60, ???sex: ‘male‘};var obj1 = {};function clone(origin, target) { ???for (var prop in origin) { ???????target[prop] = origin[prop]; ???}};clone(obj, obj1);在控制台中查看obj1，会发现实现了对obj的拷贝。
我们再对这个方法进行一些完善：有可能用户在执行clone方法时，只传origin一个参数，然后将函数执行结果赋给对象obj1，所以我们需要在方法最下方加一个返回值target，返回克隆结果，相应的也要在函数体里声明var target = {};
还有一种情况obj1对象里事先有其他属性，那么函数体里写 var target = target || {};
function clone(origin, target) { ???var target = target || {}; ???for (var prop in origin) { ???????target[prop] = origin[prop]; ???} ???return target;}var obj = { ???????????name: ‘隔壁老王‘, ???????????age: 60, ???????????sex: ‘male‘, ???????????card: [‘信用卡‘, ‘借记卡‘, ‘理发卡‘], ???????????wife: { ???????????????name: ‘小刘‘, ???????????????son: { ???????????????????name1: ‘王小宝‘, ???????????????????name2: ‘王二宝‘ ???????????????} ???????????}, ???????????divorce: function () { } ???????}; ???????var obj1 = { ???????????father: "老王" ???????}; ???????function deepClone(origin, target) { ???????????var target = target || {}, ???????????????toStr = Object.prototype.toString, ???????????????arrStr = ‘[object Array]‘; ???????????for (var prop in origin) { ???????????????if (origin.hasOwnProperty(prop)) { ???????????????????if (typeof (origin[prop]) == ‘object‘ && origin[prop] !== null) { ???????????????????????target[prop] = (toStr.call(origin[prop]) == arrStr) ? [] : {}; ???????????????????????deepClone(origin[prop], target[prop]); ???????????????????} else { ???????????????????????target[prop] = origin[prop]; ???????????????????} ???????????????} ???????????} ???????????return target; ???????} ???????deepClone(obj, obj1);js拷贝
原文地址：https://www.cnblogs.com/love314159/p/8687024.html