为什么 clear(） 函数在发生 onChange 事件时没有被调用

Why does the clear() function not get called when the onChange event occurs?

本文关键字：事件 调用 onChange clear 函数 为什么      更新时间：2023-09-26

我正在完成一个关于Javascript表单验证的练习。在我的代码中，我有一个包含三列的表：表单名称、表单、验证消息。当表单验证期间发生错误时，消息将显示在第三列中。当表单元素更改时 - 错误消息应该消失，但它不会。似乎根本没有调用 clear（） 函数。有人可以帮我吗 - 谢谢！

<html>
<head>
<title>Validation</title>
<script type="text/javascript">
    function clear()
    {
        for(var i in document.getElementsByName("error"))
        {
            document.getElementsByName("error")[i].innerHTML = "";
        }
    }

    function validate()
    {
        if(document.Form.Name.value.length < 1)
        {
            document.getElementsByName("error")[0].innerHTML = "Please enter your full name."
            return false;
        }
        if(document.Form.Address.value.length<3)
        {
            document.getElementsByName("error")[1].innerHTML = "Please enter full address."
            return false;
        }
        if(document.Form.Phone.value.length <6)
        {
            document.getElementsByName("error")[2].innerHTML = "Please enter a phone number."
            return false;
        }
        if(document.Form.Email.value.length <5 || "@".search(document.Form.Email.value)==-1)
        {
            document.getElementsByName("error")[3].innerHTML = "Please enter a valid e-mail address";
            return false;
        }
    }
</script>
</head>
<body>
<h1>Validation</h1>
<p>Enter the following information. When you press the Submit button, the data you entered will be validated.</p>
<form name="Form" onSubmit="return validate()">
<table>
<tr>
    <td>Name</td>
    <td><input type="text" name="Name" size="20" onchange="clear()" class="Form"></td>
    <td><div name="error"></div></td>
</tr>
<tr>
    <td>Address</td>
    <td><textarea rows="5" columns="20" class="Form" onchange="clear()" name="Address"></textarea></td>
    <td><div name="error"></div></td>
</tr>
<tr>
    <td>Phone</td>
    <td><input type="text" name="Phone" onchange="clear()" size="11" class="Form"></td>
    <td><div name="error"></div></td>
</tr>
<tr>
    <td>E-mail</td>
    <td><input type="text" name="Email" onchange="clear()" size="20" class="Form"></td>
    <td><div name="error"></div></td>
</tr>
</table>
<input type="submit" value="Submit" >
<input type="button" value="Clear" onClick="clear();">
</form>
</body>
</html>

试试这个

 <html>
    <head>
<title>Validation</title>
</head>
<body>
<h1>Validation</h1>
<p>Enter the following information. When you press the Submit button, the data you entered will be validated.</p>
<form name="Form" onSubmit="return validate()">
<table>
<tr>
    <td>Name</td>
    <td><input type="text" name="Name" size="20" onkeypress="return clearErrors();" class="Form"></td>
    <td><div name="error"></div></td>
</tr>
<tr>
    <td>Address</td>
    <td><textarea rows="5" columns="20" class="Form" onkeypress="return clearErrors();" name="Address"></textarea></td>
    <td><div name="error"></div></td>
</tr>
<tr>
    <td>Phone</td>
    <td><input type="text" name="Phone" onkeypress="return clearErrors();" size="11" class="Form"></td>
    <td><div name="error"></div></td>
</tr>
<tr>
    <td>E-mail</td>
    <td><input type="text" name="Email" onkeypress="return clearErrors();" size="20" class="Form"></td>
    <td><div name="error"></div></td>
</tr>
</table>
<input type="submit" value="Submit" >
<input type="button" value="Clear" onClick="return clearErrors();">
</form>
<script type="text/javascript">
    function clearErrors()
        { 
            var arr = new Array(); 
            arr = document.getElementsByName('error'); 
            for (var i = 0; i < arr.length; i++) { 
                document.getElementsByName('error')[i].innerHTML = "";
            }      
        return true;
    }

    function validate()
    {
        if(document.Form.Name.value.length < 1)
        {
            document.getElementsByName("error")[0].innerHTML = "Please enter your full name."
            return false;
        }
        if(document.Form.Address.value.length<3)
        {
            document.getElementsByName("error")[1].innerHTML = "Please enter full address."
            return false;
        }
        if(document.Form.Phone.value.length <6)
        {
            document.getElementsByName("error")[2].innerHTML = "Please enter a phone number."
            return false;
        }
        if(document.Form.Email.value.length <5 || "@".search(document.Form.Email.value)==-1)
        {
            document.getElementsByName("error")[3].innerHTML = "Please enter a valid e-mail address";
            return false;
        }
    }
</script>
</body>
</html>
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