1 <html lang="en"> 2 3 <head> 4 <meta charset="UTF-8"> 5 <meta name="viewport" content="width=device-width, initial-scale=1.0"> 6 <meta http-equiv="X-UA-Compatible" content="ie=edge"> 7 <title>一次定时器</title> 8 </head> 9 10 <body> 11 <button id="btn">3秒后释放</button> 12 <button id="btn1">停止</button> 13 <script> 14 window.onload = function() { 15 //1.获取标签 16 var btn = document.getElementById('btn'); 17 var btn1 = document.getElementById('btn1'); 18 var timer = null; 19 btn.onclick = function() { 20 clearTimeout(timer) 21 timer = setTimeout(function() { 22 alert('3秒释放') 23 }, 3000) 24 } 25 btn1.onclick = function() { 26 clearTimeout(timer) 27 } 28 } 29 </script> 30 </body> 31 32 </html>