Comparison of 6 methods of JavaScript array traversal

This article will compare 6 JS array traversal methods: for, foreach, for in, for of, . each, ().each, and introduce their differences. It has certain reference value. Friends in need can refer to it. I hope it will be helpful to everyone.

6 JS array traversal methods

1. for

In Javascript The for loop, which is used to traverse the array

function* fibonacci() { // a generator function let [prev, curr] = [0, 1]; while (true) { [prev, curr] = [curr, prev + curr]; yield curr; } } for (let n of fibonacci()) { console.log(n); // truncate the sequence at 1000 if (n >= 1000) { break; } }

五、jQuery里面的$.each

$.each(arr|obj, function(k, v))
可以用来遍历数组和对象，其中k表示索引值或者key值，v表示value值

var arr = ['a','b','c'] $.each(arr, function(key, val) { console.log(key, val); }) //0 a //1 b //2 c

六、jQuery里面的$().each()

$().each()在dom处理上面用的较多,主要是用来遍历DOMList。如果页面有多个input标签类型为checkbox，对于这时用$().each()来处理多个checkbox，例如：

$(“input[name=’checkbox’]”).each(function(i){ if($(this).attr(‘checked’)==true){ //操作代码 }

结论：

推荐在循环对象属性的时候使用for in,在遍历数组的时候的时候使用for of；
for in循环出的是key，for of循环出的是value；
for of是ES6新引入的特性。修复了ES5的for in的不足；
for of不能循环普通的对象，需要通过和Object.keys()搭配使用。

跳出循环的方式有如下几种：
return 函数执行被终止；
break 循环被终止；
continue 循环被跳过。

更多编程相关知识，请访问：编程视频！！

The above is the detailed content of Comparison of 6 methods of JavaScript array traversal. For more information, please follow other related articles on the PHP Chinese website!