Question

我正在尝试更正表单，但javascript代码不会坚持。有谁知道问题可能是什么？我试过几个小时但浏览器不会识别任何javascript代码..

HTML

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Page title</title>
    <link rel="stylesheet" href="style/structure.css" type="text/css" />
    <link rel="stylesheet" href="style/form.css" type="text/css" />
    <link rel="stylesheet" href="style/theme.css" type="text/css" />
    <script type ="text/javascript" src ="scripts/validate.js"></script>
</head>

文件结构有问题。我在文件夹“scripts”中有javascript文件，文件名是“validate.js”。一切都应该有效，但它不会......

的Javascript

window.onload = function() {
    var form = document.getElementsByTagName("form")[0];
    form.onsubmit = validate;

    function validate() {

      var firstName = document.getElementById("field_firstname").value;

      if (firstName.length == 0) {
        alert("Please enter your first name");
        document.getElementById("field_firstname");
        return false;
      }

      var lastName = document.getElementById("field_lastname").value;
      if (lastName.length == 0) {
        alert("Please enter your last name");
        document.getElementById("field_lastname");
        return false;
      }

      var email = document.getElementById("field_email").value;
      if (email.length == 0) {
        alert("Please enter your full e-mail adress");
        document.getElementById("field_email");
        return false;
      }

      if (confirm("Do you wish to complete the registration?")) {
        return true;
      } else {
        alert("The registration was cancelled");
        return false;
      }

Answer 1

您的代码正常运行（请参阅附带的代码段）。

我发现您发布的代码中存在一些支撑问题。验证和onload函数未关闭（缺失}）

加载脚本时可能也会触发onload。您可能想测试是否调用onload函数。（调试器; console.log（）或警报（'onload'）;

window.onload=function(){
var form = document.getElementsByTagName("form")[0];
form.onsubmit = validate;
}



function validate() {

    var firstName = document.getElementById("field_firstname").value;

    if (firstName.length == 0) {
        alert("Please enter your first name");
        document.getElementById("field_firstname");
        return false;
    }

    var lastName = document.getElementById("field_lastname").value;
    if (lastName.length == 0) {
        alert("Please enter your last name");
        document.getElementById("field_lastname");
        return false;
    }

    var email = document.getElementById("field_email").value;
    if (lastName.length == 0) {
        alert("Please enter your full e-mail adress");
        document.getElementById("field_email");
        return false;
    }

    if (confirm("Do you wish to complete the registration?")) {
        return true;
    } else {
        alert("The registration was cancelled");
        return false;
    }
}

<form>
 field_firstname<input id="field_firstname" type="text"><br/>
 field_lastname<input id="field_lastname" type="text"><br/>
 field_email<input id="field_email" type="text"><br/>
 <input type="submit">
</form>

Javascript - 更正表格

1 个答案: