<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
//js中有两种for循环
//第一种循环的是下标和key
<script>
var a=[11,22,33,44]
for (var item in a){
//循环的是a的索引
console.log(a[item])
}
//循环字典操作
var b={"k1":"v1","k2":"v2",}
for (var item in b){
console.log(b[item])
}
</script>
//for循环产生下标 不支持字典操作
<script>
var a=[11,22,33,44]
for (var i =0;i<a.length;i++){
console.log(a[i])
}
</script>
</body>
</html>