JavaScript keycode allow number and plus symbol only
Question
I have this JavaScript function that is used to force user only type number in the textbox. Right now and I want to modify this function so it will allow the user to enter plus (+) symbol. How to achieve this?
//To only enable digit in the user input
function isNumberKey(evt)
{
var charCode = (evt.which) ? evt.which : event.keyCode
if (charCode > 31 && (charCode < 48 || charCode > 57))
return false;
return true;
}
8 answers
solution1
14 ACCPTED 2011-04-04 07:07:22
Since the '+' symbol's decimal ASCII code is 43, you can add it to your condition.
for example :
function isNumberKey(evt)
{
var charCode = (evt.which) ? evt.which : event.keyCode
if (charCode != 43 && charCode > 31 && (charCode < 48 || charCode > 57))
return false;
return true;
}
This way, the Plus symbol is allowed.
solution2
7 2011-04-04 07:04:16
This code might work. I added support for SHIFT + (equal sign) and the numpad + .
function isNumberKey(evt)
{
var charCode = (evt.which) ? evt.which : event.keyCode;
var shiftPressed = (window.Event) ? e.modifiers & Event.SHIFT_MASK : e.shiftKey;
if ((shiftPressed && charCode == 187) || (charCode == 107))
{
return true;
} else if ((charCode > 95) && (charCode < 106)) {
return true;
} else if (charCode > 31 && (charCode < 48 || charCode > 57))) {
return false;
} else {
return true;
}
}
solution3
3 2015-10-16 08:39:55
It's Work. Javascript keycode allow number and plus symbol only
<!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8"> <title>JavaScript form validation</title> </head> <body> <form name="form1" action="#"> Mobile Number: <input type='text' id='PhoneNumber' maxlength="10" onKeyPress="return IsNumeric3(event);" ondrop="return false;" onpaste="return false;"/> <span id="error3" style="color: Red; display: none">* Input digits (0 - 9)</span> </form> <script type="text/javascript"> var specialKeys = new Array(); specialKeys.push(8); specialKeys.push(43); specialKeys.push(37); specialKeys.push(39); //Backspace function IsNumeric3(e) { var keyCode = e.which ? e.which : e.keyCode var ret = (keyCode != 37 && keyCode != 8 && keyCode != 46 && (keyCode >= 48 && keyCode <= 57) || specialKeys.indexOf(keyCode) != -1); document.getElementById("error3").style.display = ret ? "none" : "inline"; return ret; } </script> <script> function stringlength(inputtxt, minlength, maxlength) { var field = inputtxt.value; var mnlen = minlength; var mxlen = maxlength; if(field.length<mnlen || field.length> mxlen) { alert("Please input the 10 digit mobile number"); return false; } else { return true; } } </script> </body> </html>
Thank you friends
solution4
3 2011-04-04 07:04:39
this is stupid ... not really an answer at all. I would suggest you to do following.
function isNumberKey(evt)
{
console.log(evt.keyCode);
return false;
}
And find out the ranges of all keys, and implement it.
solution5
1 2011-04-04 07:31:17
Here is the modified code:
function isNumberKey(evt)
{
var charCode = (evt.which) ? evt.which : event.keyCode
if ( (charCode >= 48 && charCode <= 57) || charCode == 43)
return true;
return false;
}
solution6
0 2017-07-01 11:36:50
Here is the code . working fine with numbers and plus + sign in phone fields. you will have to implement the code on keydown function . target the id/class of the particular phone field and use keydown function.
//allows only these keys
// backspace, delete, tab, escape, and enter
if ( event.keyCode == 107 || event.keyCode == 46 || event.keyCode == 8 || event.keyCode == 9 || event.keyCode == 27 || event.keyCode == 13 ||
// Ctrl+A
(event.keyCode == 65 && event.ctrlKey === true) ||
// home, end, left, right
(event.keyCode >= 35 && event.keyCode <= 39)) {
return;
}
else {
// Ensure that it is a number and stop the keypress
if (event.shiftKey || (event.keyCode < 48 || event.keyCode > 57) && (event.keyCode < 96 || event.keyCode > 105 )) {
event.preventDefault();
}
}
solution7
0 2018-01-24 18:23:31
Using experience of my colleagues above, write one function, that fits me well. It filters all except numbers, arrows and backspace. Maybe it would be useful for somebody.
function isKeyCorrect(keyEvent) {
var charCode = keyEvent.which ? keyEvent.which : keyEvent.keyCode;
var isNotNumber = charCode < 48 || charCode > 57;
var isNotArrow = charCode < 37 || charCode > 40;
var isNotBackspace = charCode !== 8;
return isNotNumber && isNotArrow && isNotBackspace;
}
solution8
-3 2014-10-26 18:57:25
<script type="text/javascript">
$(document).ready(function() {
`enter code here` $('#form-1').submit(function(msg) {
$.post("action.php?act=login",$(this).serialize(),function(data){
if (data == 'ERR:A3001004') { alert("Güvenlik hatası, sayfayı yenileyin."); }
else if (data == 'TIMEEND') { alert("Anahtarınızın süresi dolmuş."); }
else if (data == 'INVALID') { alert("Geçersiz anahtar şifresi girdiniz."); }
else if (data == 'OK') { alert("Başarıyla giriş yaptınız. Yetişkinlere göre içerik barındıran sitelere erişim sağlayabilirsiniz."); }
});
return false;
});
});
function isNumberKey(evt)
{
var charCode = (evt.which) ? evt.which : event.keyCode
if (charCode > 31 && (charCode < 48 || charCode > 57))
return false;
return true;
}
</script>
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