本文实例讲述了js常见遍历操作。分享给大家供大家参考，具体如下：
for循环
var a = new Array("first", "second", "third") for(var i = 0;i < a.length; i++) {document.write(a[i]+",");} for in
var arr = new Array("first", "second", "third") for(var item in arr) {document.write(arr[item]+",");} for each
<button onclick="numbers.forEach(myFunction)">点我</button><p id="demo"></p><script>demoP = document.getElementById("demo");var numbers = [4, 9, 16, 25];function myFunction(item, index) { demoP.innerHTML = demoP.innerHTML + "index[" + index + "]: " + item + "<br>"; }</script> var arr = [1,2,3,4];arr.forEach(function(value,index,array){ array[index] == value; //结果为true sum+=value; });console.log(sum); //结果为 10 each
$.each([],function(index,value,array){ //code something }) map
[].map(function(value,index,array){ //code}) 希望本文所述对大家JavaScript程序设计有所帮助。
注：相关教程知识阅读请移步到JavaScript/Ajax教程频道。
