停止之后怎樣再次啟動
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>計時器</title>
<script type="text/javascript">
?? function clock(){
????? var time=new Date();????????????? ??? ? ?
????? document.getElementById("clock").value = time;
???? ?
?? }
??? var i=setInterval('clock()',100);
?? ?
</script>
</head>
<body>
? <form>
??? <input type="text" id="clock" size="50"? />
??? <input type="button" value="Stop" onclick='clearInterval(i)' />
??? <input type='button'value='start' onclick='clock()'>
? </form>
</body>
</html>
2019-12-27
<input?type='button'value='start'?onclick='setInterval("clock()",100)'>