数组深浅拷贝

[Lee981265]

数组的浅拷贝

拓展运算符 (数组 字符串 对象皆可操作)

// 拷贝a
let a = [1,2]
let b = [...a]  // [1,2]

// 字符串转数组
let str = 'hello'
let arr = [...a] // ['h','e','l','l','e']

// 对象拷贝
let obj = {a:1,b:2}
let newObj = {...obj} // {a:1,b:2}

slice

let arr = [1,2]
let newArr = arr.slice()

concat

let arr = [1,2]
let newArr = arr.concat()

JSON序列化 不建议

JSON.parse(JSON.stringify(obj))

数组的深拷贝

 var c = [{a:1},{b:2}]
 var d = [...c.map(_ => ({...c}))]

copyArray(arr) {
    var newArr = arr.constructor === Array ? [] : {};
    if (typeof arr !== 'object') {
      return;
    }
    for (var i in arr) {
      newArr[i] = typeof arr[i] === 'object' ? this.copyArray(arr[i]) : arr[i];
    }
    return newArr;
  }