问使用js的验证不会更新为span
EN

Stack Overflow用户

提问于 2020-05-08 01:47:36

回答 3查看 83关注 0票数 1

我写这段代码是为了验证js的用户输入，但它似乎没有输入脚本。我认为问题是"onkeyup“对我不起作用。

<script language="JavaScript">
var flag  = false ;


function checkCat(value)
{

    var validate = /^[a-z]{3,15}$/i ;

    if( value.length ==0 )
    {
        re = '';
        flag = false ;
    }

    else if(!validate.test(value))
    {

        flag = false ;
        re = 'Invalid';
        col = 'red' ;


    }
    else
    {
        flag = true ;
        re = 'Valid';
        col = 'green' ;
    }
    document.getElementById('print').style.color = col ;
    document.getElementById('print').innerHTML = re ;

}
function checkForm ()
{
    document.catForm.JSEnabled.value="TRUE";
    return flag ;
}
</script>

上面的代码在头部，下面的代码在身体部分

<form method = 'post' name = 'catForm' onsubmit="return checkForm();" >


                       <input type="text"   name = 'cat' placeholder="Category name" onkeyup='checkCat(this.value)'> <span id='print'></span> <br/>
                        <input type='hidden' name='JSEnabled' value='FALSE' />



                  <input id="submit" type="submit" name = 'sb' value="Add A New Category" >

javascript

html

regex

回答 3

Stack Overflow用户

回答已采纳

发布于 2020-05-08 02:16:25

我甚至用HTA扩展测试了它，一切都很好！

<!DOCTYPE html>
<html>
<title>validation using js is not updating to span</title>
<head>
<script language="JavaScript">
var flag  = false ;
function checkCat(value)
{
    var validate = /^[a-z]{3,15}$/i ;
    if( value.length ==0 )
    {
        re = '';
        flag = false ;
    }

    else if(!validate.test(value))
    {

        flag = false ;
        re = 'Invalid';
        col = 'red' ;


    }
    else
    {
        flag = true ;
        re = 'Valid';
        col = 'green' ;
    }
    document.getElementById('print').style.color = col ;
    document.getElementById('print').innerHTML = re ;
}
function checkForm ()
{
    document.catForm.JSEnabled.value="TRUE";
    return flag ;
}
</script> 
</head>

<body>
<form method = 'post' name = 'catForm' onsubmit="return checkForm();" >
<input type="text"   name = 'cat' placeholder="Category name" onkeyup='checkCat(this.value)'> <span id='print'></span> <br/>
<input type='hidden' name='JSEnabled' value='FALSE' />
<input id="submit" type="submit" name = 'sb' value="Add A New Category" >
</body>
</html>

票数 0

Stack Overflow用户

发布于 2020-05-08 02:05:35

看起来它像预期的那样工作：

<!DOCTYPE html>
<html>
<head>
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>
</head>
<body>

   <form method='post' name='catForm' onsubmit="return checkForm();">

    <input type="text" name='cat' placeholder="Category name" onkeyup='checkCat(this.value)'> <span id='print'></span> <br />
    <input type='hidden' name='JSEnabled' value='FALSE' />

    <input id="submit" type="submit" name='sb' value="Add A New Category">
</form>
    <script>
        var flag = false;

        function checkCat(value) {

            var validate = /^[a-z]{3,15}$/i;

            if (value.length == 0) {
                re = '';
                flag = false;
            }

            else if (!validate.test(value)) {

                flag = false;
                re = 'Invalid';
                col = 'red';

            }
            else {
                flag = true;
                re = 'Valid';
                col = 'green';
            }
            document.getElementById('print').style.color = col;
            document.getElementById('print').innerHTML = re;

        }
        function checkForm() {
            document.catForm.JSEnabled.value = "TRUE";
            return flag;
        }
    </script>
</body>
</html>