一、浅拷贝

<!-- 应用场景:复杂数据类型 -->
    <script>
        /* 简单的赋值:浅拷贝 */
        var arr = [1,2,3,4];
        var newArr = arr;
        newArr.push(5);
        console.log(arr);
    </script>

二、深拷贝

2-1.简单数据类型

<!-- 赋值运算的时候只赋值 -->
    <!-- 赋值运算中
    浅拷贝:指向的是堆内存中的同一个对象
    深拷贝:指向堆内存中的不同对象
    -->
    <script>
        var arr = [1,2,3,4];
        var newArr = [...arr];
        arr.push(5);
        console.log(newArr);
    </script>

<script>
        var arr = [2,3,4,5];
        var newArr = arr.slice(0,);
        newArr.push(6);
        console.log(arr);
    </script>

<script>
        var arr = [2,3,4,5];
        var newArr = [].concat(arr);
        arr.push(6);
        console.log(newArr);
    </script>

2-2.复杂数据类型

<script>
        var arr = [{name:"lisi"},{name:"wangwu"}];
        var newArr = JSON.parse(JSON.stringify(arr));
        arr[0].name = 'react';
        console.log(newArr);
    </script>

<script>
        var arr = [{ name: "lisi" }, { name: "wangwu" }];
        /* array,object,string,boolean,number */
        function deepClone(obj) {
            if (obj == null || typeof obj !="object") {
                return obj
            }
            let result;
            if (obj instanceof Array) {
                result = [];
            } else {
                result = {};
            }
            for (let key in obj) {
                result[key] = deepClone(obj[key]);
            }
            return result;
        }
        var newArr = deepClone(arr);
        arr[0].name = 'react'
        console.log(newArr);
    </script>