最新消息:Welcome to the puzzle paradise for programmers! Here, a well-designed puzzle awaits you. From code logic puzzles to algorithmic challenges, each level is closely centered on the programmer's expertise and skills. Whether you're a novice programmer or an experienced tech guru, you'll find your own challenges on this site. In the process of solving puzzles, you can not only exercise your thinking skills, but also deepen your understanding and application of programming knowledge. Come to start this puzzle journey full of wisdom and challenges, with many programmers to compete with each other and show your programming wisdom! Translated with DeepL.com (free version)

html - Handle key using javascript onkeydown - Stack Overflow

matteradmin4PV0评论

I have this code

function verifyKey(e)
{
    var keycode;
    if (window.event)
        keycode = window.event.keyCode;
    else if (e)
        keycode = e.which;
    regex=/[1-9]/;
    if(regex.test(keycode))
        return true;
    else
        void(0);
}

in the html I added an input and I add the onkeydown event onkeydown="verifyKey(event);"

I like to verify the key before it display on the text

If the key is a number or a(,) or full stop(.) then accept the key else refuse it

Thanks

I have this code

function verifyKey(e)
{
    var keycode;
    if (window.event)
        keycode = window.event.keyCode;
    else if (e)
        keycode = e.which;
    regex=/[1-9]/;
    if(regex.test(keycode))
        return true;
    else
        void(0);
}

in the html I added an input and I add the onkeydown event onkeydown="verifyKey(event);"

I like to verify the key before it display on the text

If the key is a number or a(,) or full stop(.) then accept the key else refuse it

Thanks

Share Improve this question edited Sep 26, 2011 at 12:38 Pointy 414k62 gold badges595 silver badges629 bronze badges asked Sep 26, 2011 at 12:35 RadRad 4,9414 gold badges27 silver badges28 bronze badges 0
Add a ment  | 

1 Answer 1

Reset to default 7

Here in your code you are testing the regular expression defined with the keycode, so every chearactes on the keyboard will be allowed since the keycode of every key is numbers, so you will not get the result what you expect. Instead of using the regular expression try the below code

<html>
<head>
<script type="text/javascript">
function verifyKey(e)
{
    var keycode;
    if (window.event)
        keycode = window.event.keyCode;
    else if (e)
        keycode = e.which;


    if((keycode>=48 && keycode<=57))
    {alert("if")
        return true;
    }
    else if((keycode == 188)||(keycode == 190))
    {alert("elseif");
        return true;
    }
    else
    {alert("else")
        return false;
    }
}


</script>
</head>
<body>
<input type="text" onkeypress="return verifyKey(event)" />
</body>
</html>
Post a comment

comment list (0)

  1. No comments so far