A simple comparison of two methods for clearing array elements in JavaScript_javascript skills

The example in this article describes a simple comparison of two methods of clearing array elements in JavaScript. Share it with everyone for your reference. The specific analysis is as follows:

There are many ways to clear arrays in JavaScript:

var arr = [1, 2, 3]; 
arr = [];//方法一
arr.length = 0;//方法二
arr = null;//方法三
delete arr;//方法四

Here are the most commonly used first and second types

var arr = [1, 2, 3];
// 方法一
// 优点：如果有其他地方用到了数组arr中的元素，这种方法相对来说更安全。并且也简单快捷
// 缺点：增加了额外的内存开销，重新开辟了一个新的空数组
arr = [];
// 方法二
// 优点：如果其他用到arr元素的地方想同步观察到arr元素被清空的效果，那么用这个是较好的选择
// 缺点：设置数组的length属性后，会导致数组删除index为length及其之后的元素，这样性能开销很大
// 这种方法也是四种方法中性能最差的。
arr.length = 0;

I hope this article will be helpful to everyone’s JavaScript programming design.