1. for/in
遍历对象属性成员。
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>TestJS</title>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
</head>
<script type = "text/javascript">
function init() {
var o = {x:1,y:2,z:3};
for(var s in o){ console.log(s);}
}
</script>
<body onload=init()>
sam
</body>
</html>
输出
x TestJS.html (line 10) y TestJS.html (line 10) z TestJS.html (line 10)
遍历属性的值
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>TestJS</title>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
</head>
<script type = "text/javascript">
function init() {
var o = {x:1,y:2,z:3};
for(var s in o){ console.log(o[s]);}
}
</script>
<body onload=init()>
sam
</body>
</html>
输出
1 TestJS.html (line 10) 2 TestJS.html (line 10) 3 TestJS.html (line 10)
遍历数组的值, 索引等于数组的属性
for(i in a) console.log(a[i]);