<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Document</title> </head> <body> <input type="button" value="alert" id="btn1"> <input type="button" value="prompt" id="btn2"> <input type="button" value="confirm" id="btn3"> <script> var btn1 = document.getElementById('btn1'); var btn2 = document.getElementById('btn2'); var btn3 = document.getElementById('btn3'); btn1.onclick = function () { alert('hello world'); } btn2.onclick = function () { // 弹出提示,让用户输入内容 var userName = prompt('请输入姓名', '张三'); console.log(userName); } btn3.onclick = function () { var isSure = confirm('是否要删除数据?'); console.log(isSure); } </script> </body> </html>