JS 浅层複製 与 深层複製 DAY60

浅层複製 ( shallow copy )

for in 写法

// 浅层複製var family = {    home: '小黑家',    members:{        mom: '老妈',        father: '老爸',        black: '小黑',    }}var newFamily = {};for(var key in family){    console.log(key); // home members (family第一层属性)    newFamily[key] = family[key];}console.log(newFamily,family);// 修改第一层属性 newFamily.home = '大雄家';console.log(newFamily,family); // 大雄家 小黑家console.log(newFamily === family); // false// 修改第二层属性newFamily.members.black = '大黑';console.log(newFamily,family); // 大黑 大黑console.log(newFamily === family); // false// 且会发现 两个同时都会改 所以只能做到第一层的複製

jQuery 写法

var newFamily2 = jQuery.extend({},family);

ES6 写法

var newFamily3 = Object.assign({},family);

深层複製(deep copy)
透过 JSON.stringify 先转字串 再透过 JSON.parse 转成物件

var family = {    home: '小黑家',    members:{        mom: '老妈',        father: '老爸',        black: '小黑',    }}var newFamily4 = JSON.parse(JSON.stringify(family));newFamily4.home = '小白家';newFamily4.members.black = '大黑';console.log(family,newFamily4); // 小黑家 小黑 ， 小白家 大黑console.log(family === newFamily4); // false

那今天的介绍就到这里
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