?????? ??? ?
JavaScript ???
JavaScript ???? ???? ???(???)? ??? ?? ??? ??? ? ????.
??:
switch (expr) {
??? ??1:
?1
break;
??? ??2:
?2
break;
……
???:
?
}
?? ??
???? expr? ?? ???? ?? ??(result1, result2 ?)? ???? ?? ?? ?? ???? ?????. ?? ?? ??? ???? ??? default? ?? ?????.
break? ?? ?? ? ?????? ???? ? ?????. ?????? ?? ?????, ??? ??? ??? ???? ???. ??? ??? ??? expr ??? ????? ?? ??? ???? ?????. ????? ???? ????(if else?? ???).
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>php中文網(wǎng)(php.cn)</title>
<script type="text/javascript">
var x = 2;
switch (x) {
case 0:
alert("x等于0");
break;
case 1:
alert("x等于1");
break;
case 2:
alert("x等于2");
break;
default:
alert("x既不等于1和2，也不等于0");
}
</script>
</head>
<body>
</body>
</html>Tips
?? ???? ??? ??? ?????
case ?? ??? ??? ???? ?? ??? JavaScript?? ???? ?? ??? ?????
?? ???
???? ????? ??? ?? ??? ?? ? ??? ??? ?????:
<html>
<head>
<meta charset="utf-8">
<title>php中文網(wǎng)(php.cn)</title>
</head>
<body>
<button onclick="myFunction()">點(diǎn)擊這里</button>
<p id="demo"></p>
<script>
function myFunction()
{
var x;
var d=new Date().getDay();
switch (d)
{
case 6:x="今天是星期六";
break;
case 0:x="今天是星期日";
break;
default:
x="期待周末";
}
document.getElementById("demo").innerHTML=x;
}
</script>
</body>
</html>
