<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title>Document</title> </head> <body> <script type="text/javascript"> let arr=[1,3,5,7,9]; for(let i=0;i<arr.length;i++) { //console.log(arr[i]); } // 2.利用forin循环来遍历数组 for(let key in arr) { // console.log(arr[key]); } function Person() { this.name = "lnj"; this.age = 34; this.score = 99; } let p = new Person(); //console.log(p); // 3.利用ES6中推出的for of循环来遍历数组 for(let value of arr) { console.log(value); } // 4.还可以利用Array对象的forEach方法来遍历数组 /*arr.forEach(function(a,b,c)
{
console.log(a,b,c);
});*/ Array.prototype.myForEach=function(fn) { for(let i=0;i<this.length;i++) { fn(this[i],i,this); } } arr.myForEach(function(a,b,c) { console.log(a,b,c); }); </script> </body> </html>
forin forof forEach myForEach
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