<!DOCTYPE html>
<!--
计时器
-->
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<p id="result"></p>
<input type="button" id="start">开始
<input type="button" id="end">结束
<!--<span id="start">开始</span>
<span id="end">结束</span>-->
<script>
var n = 0;
var start = document.getElementById("start");
var end = document.getElementById("end");
var timer;
start.onclick = function () {
timer = setInterval(function () {
document.getElementById("result").innerHTML = n;
n++;
},1000);
};
end.onclick = function () {
clearInterval(timer);
}
</script>
</body>
</html>