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javascript - 使用 JavaScript 进行实时验证

转载 作者:行者123 更新时间:2023-12-02 18:56:43 25 4
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  • 我这里有一个文本框验证。错误消息不会作为警报出现,而是会打印在 html div 标记中。

HTML:

    <div id="error" style="position:absolute; left:auto; top:7px;"></div>
<div style="position:absolute; left:auto; top:25px;">
First name: <input type="text" id="fname" name="fname"><br>
Last name: <input type="text" id="lname" name="lname"><br>
<input type="submit" value="Submit" onclick="requiredFields()"><div>

Javascript:

function requiredFields(){
var fName = document.getElementById("fname").value;
var lName = document.getElementById("lname").value;
if(fName == ""){
document.getElementById("error").innerHTML = "First name field cannot be empty";
}else if(lName == ""){
document.getElementById("error").innerHTML = "Last name field cannot be empty";
}else{
document.getElementById("error").innerHTML = "";
alert("successful");
}
}
  • 单击按钮后,将打印错误消息。
  • 我的问题是,JavaScript 中有实时验证吗?
  • 我的意思是,首先错误消息应该出现在单击按钮时,以及用户在文本框中输入值时,如果名字文本框有任何值,我需要清除错误消息而无需再次单击按钮.

只需检查我的链接并帮助我.. http://jsfiddle.net/GACKm/

最佳答案

这是jsFiddle

//Javascript

<script type="text/javascript" language="javascript">
var oneTimeMsgClikced = false;
function requiredFields() {
var fName = document.getElementById("fname").value;
var lName = document.getElementById("lname").value;
if (fName == "") {
document.getElementById("error").innerHTML = "First name field cannot be empty";
oneTimeMsgClikced = false;
} else if (lName == "") {
document.getElementById("error").innerHTML = "Last name field cannot be empty";
oneTimeMsgClikced = false;
} else {
document.getElementById("error").innerHTML = "";
if (oneTimeMsgClikced == false) {
alert("successful");
oneTimeMsgClikced = true;
}
}
}
</script>

//html代码

<body>
<div id="error" style="position: absolute; left: auto; top: 7px;">
Errors here
</div>
<div style="position: absolute; left: auto; top: 25px;">
First name:
<input type="text" id="fname" name="fname" onblur="requiredFields()" />
<br />
Last name:
<input type="text" id="lname" name="lname" onblur="requiredFields()"/>
<br />
<input type="submit" value="Submit" onclick="requiredFields()" />
</div>
</body>

关于javascript - 使用 JavaScript 进行实时验证,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/15264501/

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