html运行实例（eg_js_timing_setinterval_clearinterval

代码示例：（标识：eg_js_timing_setinterval_clearinterval_2）

<!DOCTYPE html>
<html>
<body>

<button onClick="setInterval(myCounter, 1000)">启动计数器</button>

<p id="demo">点击上面的按钮，我会永远计数。</p>

<script>
var c = 0;
function myCounter() {
  document.getElementById("demo").innerHTML = ++c;
}
</script> 

</body>
</html>