- 深拷贝：修改复制对象，原始对象不会变化
- 浅拷贝：修改复制对象，原始对象也变化
方式：
- 遍历赋值
- Object.create()
- JSON.parse()和JSON.stringify()
操作的对象
var obj = { a: "Hello", b: { a: "world", b: 111, }, c: [11, "Jack", "Tom"], };
1、浅拷贝
1-1、遍历赋值
// 浅拷贝 function simpleCopy(o) { var o_ = {}; for (let i in o) { o_[i] = o[i]; } return o_; } var newObj = simpleCopy(obj); newObj.b.a = "WORLD"; console.log(obj); console.log(newObj); /** obj 和 newObj都变了： b: { "a": "WORLD", "b": 111}} */
1-2、Object.create()
var newObj = Object.create(obj); newObj.b.a = "WORLD"; console.log(obj); // b: {a: "WORLD", b: 111} console.log(newObj); // __proto__: // b: {a: "WORLD", b: 111}
2、深拷贝
2-1、遍历赋值
function deepCopy(object, deepObject=null) { let deepObj = deepObject || {}; for (let i in object) { if (typeof object[i] === "object") { // 引用类型 [] {} null if(object[i] === null){ deepObj[i] = object[i]; } else{ deepObj[i] = object[i].constructor === Array ? []: {} // deepObj[i] = object[i].constructor === Array ? []: Object.create(null); deepCopy(object[i], deepObj[i]) } } else{ // 简单数据类型 deepObj[i] = object[i]; } } return deepObj; } var newObj = deepCopy(obj); newObj.b.a = "WORLD"; console.log(obj); // b: {a: "world", b: 111} console.log(newObj); // b: {a: "WORLD", b: 111}
2-2 JSON
function deepCopy(o) { return JSON.parse(JSON.stringify(o)); } var newObj = deepCopy(obj); newObj.b.a = "WORLD"; console.log(obj); // b: {a: "world", b: 111} console.log(newObj); // b: {a: "WORLD", b: 111}
