<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Document</title>
</head>
<body>
手机号码：<input type="number" /><button>发送</button>
<script>
var btn = document.querySelector("button");
var num = 5;//定义剩下的秒数
btn.addEventListener("click", function() {
btn.disabled = true;
var timer = setInterval(function() {
if (num == 0) {
//清除定时器和复原定时器
clearInterval(timer);
btn.disabled = false;
btn.innerHTML = "发送";
num = 3; //不要忘记还要从原来的num数重新开始
} else {
btn.innerHTML = "还剩" + num + "秒";
num--;
}
}, 1000);
});
</script>
</body>
</html>
