代码语言：javascript复制
<!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>
