Question

我有这个javascript代码：

function validate()
{

    var email=document.getElementById('email').value;


    var emailRegex=/^[a-z0-9._-]+@[a-z0-9._-]+\.[a-z]{2,6}$/;
    var emailResult=emailRegex.test(email);
    alert("email:" +emailResult);
}

和表单标签上的html部分：

<input type="text" id="email" placeholder="EMAIL"><br><br>
<input type="submit" value="REGISTER" id="butt">

我希望每次Regex的测试返回false时都会打印一条消息，但我不想使用警告框。我怎么能这样做？

表格：

         <form id="registration" onsubmit="validate()">
                <h3>S'ENREGISTRER</h3>
                <label for="button">FULL NAME: </label>
                <small>*</small>
                <input type="text" name="fname" id="fullname" placeholder="FULL NAME"><br><br>
                <label for="button">LAST NAME:</label>
                <small>*</small>
                <input type="text" name="lname" id="lastname" placeholder="LAST NAME"><br><br>
                <label for="button">USERNAME:</label>
                <small>*</small>
                <input type="text" name="uname" id="username" placeholder="USERNAME"><br><br>
                <label for="button">PASSWORD:</label>
                <small>*</small>
                <input type="password" name="pass" id="password" placeholder="PASSWORD"><br><br>
                <label id = "kjo" for="button">EMAIL:</label>
                <small>*</small>
                <input type="text" id="email" placeholder="EMAIL"><br><br>
                <input type="submit" value="REGISTER" id="butt" onclick="validate()">
                <p id="result"></p>
                <br><br>
                <a href="login.html">LOGIN</a>
            </form>

Answer 1

一种可能性是添加p代码（或div，span等），用作＆＃34;字段＆＃34;显示测试结果。

在这种情况下，我使用p标记。要打印结果，我使用innerText，如下所示：

＆＃13;

function validate() {

  var email = document.getElementById('email').value;


  var emailRegex = /^[a-z0-9._-]+@[a-z0-9._-]+\.[a-z]{2,6}$/;
  var emailResult = emailRegex.test(email);
  //alert("email:" + emailResult);
  // Show result withing the added p tag
  document.getElementById('result').innerText = "email: " + emailResult;
}

＆＃13;

<input type="text" id="email" placeholder="EMAIL"><br><br>
<input type="submit" value="REGISTER" id="butt" onclick="validate()">
<p id="result"></p>

＆＃13;

PS：我还在您的按钮中添加了onclick属性，以便在点击按钮时触发该功能。

修改

如果要显示错误消息，表单提交后，您可能需要查看PHP。在客户端使用JavaScript（我们在这里做的），你无法做到这一点。

解决此问题的一种方法是，如果电子邮件无效，则阻止表单提交：

＆＃13;
＆＃13;
function validate(event) { // Mind the "event" parameter here var email = document.getElementById('email').value; var emailRegex = /^[a-z0-9._-]+@[a-z0-9._-]+\.[a-z]{2,6}$/; var emailResult = emailRegex.test(email); //alert("email:" + emailResult); // Check if the email is invalid. If not, dont' submit the form if (emailResult == false) { event.preventDefault(); // This line prevents the form from submitting document.getElementById('result').innerText = "email: " + emailResult; } }
＆＃13;
<form id="registration" onsubmit="validate(event)">  <h3>S'ENREGISTRER</h3> <label for="button">FULL NAME: </label> <small>*</small> <input type="text" name="fname" id="fullname" placeholder="FULL NAME"><br><br> <label for="button">LAST NAME:</label> <small>*</small> <input type="text" name="lname" id="lastname" placeholder="LAST NAME"><br><br> <label for="button">USERNAME:</label> <small>*</small> <input type="text" name="uname" id="username" placeholder="USERNAME"><br><br> <label for="button">PASSWORD:</label> <small>*</small> <input type="password" name="pass" id="password" placeholder="PASSWORD"><br><br> <label id="kjo" for="button">EMAIL:</label> <small>*</small> <input type="text" id="email" placeholder="EMAIL"><br><br> <input type="submit" value="REGISTER" id="butt">  <p id="result"></p> <br><br> <a href="login.html">LOGIN</a> </form> <p id="result"></p>
＆＃13;
＆＃13;
＆＃13;

Answer 2

如上一个答案所述，您可以在要验证的每个字段后插入标记以显示结果。

对于您提到的电子邮件，我写下了显示错误消息的部分，如下所示。

Element.prototype.remove = function() {
  this.parentElement.removeChild(this);
};
NodeList.prototype.remove = HTMLCollection.prototype.remove = function() {
  for (var i = this.length - 1; i >= 0; i--) {
    if (this[i] && this[i].parentElement) {
      this[i].parentElement.removeChild(this[i]);
    }
  }
};

function insertAfter(newNode, referenceNode) {
  referenceNode.parentNode.insertBefore(newNode, referenceNode.nextSibling);
}

function validate(event) {
  var emailInput = document.getElementById("email");
  var email = emailInput.value;

  var emailRegex = /^[a-z0-9._-]+@[a-z0-9._-]+\.[a-z]{2,6}$/;
  var emailResult = emailRegex.test(email);
  if (!emailResult) {
    var errorDiv = document.getElementById("error");
    if (!errorDiv) {
      var div = document.createElement("div");
      div.innerHTML = "Insert a valid Email";
      div.classList.add("error");
      div.id = "error";
      insertAfter(div, emailInput);
      emailInput.classList.add("error-input");
    }
    event.preventDefault();
  } else {
    var errorDiv = document.getElementById("error");
    if (errorDiv) {
      errorDiv.remove();
      emailInput.classList.remove("error-input");
    }
  }
}

.error {
  color: red;
}

.error-input {
  border: 1px solid red;
  border-radius: 5px;
  padding: 5px
}

<form id="registration" onsubmit="validate()">
  <h3>S'ENREGISTRER</h3>
  <label for="button">FULL NAME: </label>
  <small>*</small>
  <input type="text" name="fname" id="fullname" placeholder="FULL NAME"><br><br>
  <label for="button">LAST NAME:</label>
  <small>*</small>
  <input type="text" name="lname" id="lastname" placeholder="LAST NAME"><br><br>
  <label for="button">USERNAME:</label>
  <small>*</small>
  <input type="text" name="uname" id="username" placeholder="USERNAME"><br><br>
  <label for="button">PASSWORD:</label>
  <small>*</small>
  <input type="password" name="pass" id="password" placeholder="PASSWORD"><br><br>
  <label id="kjo" for="button">EMAIL:</label>
  <small>*</small>
  <input type="text" id="email" placeholder="EMAIL"><br><br>
  <input type="submit" value="REGISTER" id="butt" onclick="validate(event)">
  <p id="result"></p>
  <br><br>
  <a href="login.html">LOGIN</a>

</form>

您还可以为您的字段编写事件监听器onchange或onmouseout或onfocusout，以便在每次更改后立即对其进行验证。

希望这有帮助。

Javascript消息提示框

2 个答案: