27_发送短信.html

<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>发送短信</title>
        <style>

        </style>
    </head>
        <body>
            手机号码：<input type="number"> <button>发送</button>
            <script>
                var btn = document.querySelector('button');
                var time = 3; // 定义剩下的描述

                var fn = function(){
                    if (time === 0) {
                        // 清除定时器和复原按钮
                        clearInterval(timer);
                        btn.disabled = false;
                        btn.innerHTML = '发送';
                        time = 3;
                    } else {
                        btn.innerHTML = '还剩下' + time + '秒';
                        time -= 1;
                    }
                };
                var timer = null;
                btn.addEventListener('click', function(){
                    btn.disabled = true;
                    timer = setInterval(fn, 1000);
                })
            </script>
        </body>
    </head>
</html>