点击运行
<!DOCTYPE html> <html> <body> <p>输入数字并点击提交：</p> <input id="id1" type="number" min="100" max="300" required> <button onclick="myFunction()">提交</button> <p>如果该数字小于 100 或大于 300，将显示错误消息。</p> <p id="demo"></p> <script> function myFunction() { var inpObj = document.getElementById("id1"); if (!inpObj.checkValidity()) { document.getElementById("demo").innerHTML = inpObj.validationMessage; } else { document.getElementById("demo").innerHTML = "输入有效"; } } </script> </body> </html>
运行结果
