javascript reverse()可以顛倒數組中元素的順序，該方法會改變原來的數組，而不會創建新的數組
<!DOCTYPE html>
<html>
<head>
<title>Runde</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<script type="text/javascript">
var arr = new Array(3)
arr[0]="張三"
arr[1]="李四"
arr[2]="王五"
document.write(arr+"<br />")
document.write(arr.reverse())
</script>
</head>
<body>
</body>
</html>