源代码 ：
点击运行
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> </head> <body> <p>输入数字并点击验证按钮:</p> <input id="id1" type="number" min="100" max="300" required> <button onclick="myFunction()">验证</button> <p>如果输入的数字小于 100 或大于300，会提示错误信息。</p> <p id="demo"></p> <script> function myFunction() { var inpObj = document.getElementById("id1"); if (inpObj.checkValidity() == false) { document.getElementById("demo").innerHTML = inpObj.validationMessage; } else { document.getElementById("demo").innerHTML = "输入正确"; } } </script> </body> </html>
运行结果