2020-12-24

console.log()，对于一般对于基本类型number、string、boolean、null、undefined 的输出是可信的。但对于Object 等引用类型来说，则就会出现上述异常打印输出。（调试复杂数据类型时候通过打断点来看即可）

正常预期

  <script>var arr1 = [1,2]
//     let arr1 = [
//       {id:1,name:1},
//       {id:2,name:2}
//     ]console.log(arr1);arr1[0]=111111;console.log(arr1);</script>

打印结果
在这里插入图片描述

1.直接打印前后数组的值和预期结果一样

  <script>// var arr1 = [1,2]let arr1 = [{id:1,name:1},{id:2,name:2}]console.log(arr1);arr1[0]=111111;console.log(arr1);</script>

打印看到的结果是一致的
在这里插入图片描述

2.打印到具体的看却不一致和预期一样

  <script>// var arr1 = [1,2]let arr1 = [{id:1,name:1},{id:2,name:2}]console.log(arr1[0]);arr1[0]=111111;console.log(arr1[0]);</script>

打印结果
在这里插入图片描述

3.做判断也是不一致和预期一样

<script>// var arr1 = [1,2]let arr1 = [{id:1,name:1},{id:2,name:2}]if (arr1[0] > 1) {console.log(1,arr1);}else {console.log(2,arr1);}arr1[0]=111111;// console.log(arr1);if (arr1[0] > 1) {console.log(3,arr1);}else {console.log(4,arr1);}</script>