Allow only numeric value in textbox using Javascript

Question

I want to allow only numeric values to be entered into the text and if user enters alphabetic character it should warn the user  Any suggestion for optimized and short javascript code

User · Answer

Here is a solution which blocks all non numeric input from being entered into the text-field.

html

<input type="text" id="numbersOnly" />

javascript

var input = document.getElementById('numbersOnly');
input.onkeydown = function(e) {
    var k = e.which;
    /* numeric inputs can come from the keypad or the numeric row at the top */
    if ( (k < 48 || k > 57) && (k < 96 || k > 105)) {
        e.preventDefault();
        return false;
    }
};?

User · Answer

Please note that  you should allow  system  key as well        element  keydown function  e        var code    e keyCode   e keyCode   e which   value      if  isSysKey code     code     8    code     46            return true             if  e shiftKey    e altKey    e ctrlKey            return              if  code  gt   48  amp  amp  code  lt   57            return true             if  code  gt   96  amp  amp  code  lt   105            return true             return false       function isSysKey code        if  code     40    code     38                code     13    code     39    code     27                code     35                code     36    code     37    code     38                code     16    code     17    code     18                code     20    code     37    code     9                 code  gt   112  amp  amp  code  lt   123             return true             return false

User · Answer

Shane  you could code break anytime  any user could press and hold any text key like  hhhhhhhhh  and your could should allow to leave that value intact   For safer side  use this       testInput   keypress function event     instead of       testInput   keyup function event     I hope this will help for someone

User · Answer

or  function isNumber n     return  parseFloat n     n       http   jsfiddle net Vj2Kk 2

User · Answer

Solution to enter only numeric value in text box      num of emp   keyup function           this value   this value replace    0-9   g            for an input box such as     lt input type  text  name  number of employee  id  num of emp    gt

User · Answer

use following code  function numericFilter txb       txb value   txb value replace     0-9  ig           call it in on key up   lt input type  text  onKeyUp  numericFilter this      gt

User · Answer

function isNumber n      return  isNaN parseFloat n    amp  amp  isFinite n       from here

User · Answer

Javascript For only numeric value in textbox      lt input type  text  id  textBox  runat  server  class  form-control  onkeydown  return onlyNos event   tabindex  0    gt          lt  --Only Numeric value in Textbox Script -- gt           lt script type  text javascript  gt              function onlyNos e  t                    try                       if  window event                            var charCode   window event keyCode                                            else if  e                            var charCode   e which                                            else   return true                        if  charCode  gt  31  amp  amp   charCode  lt  48    charCode  gt  57                             return false                                            return true                                    catch  err                        alert err Description                                            lt  script gt           lt  --Only Numeric value in Textbox Script -- gt

User · Answer

This code uses the event object s  keyCode property to check the characters typed into a given field  If the key pressed is a number  do nothing  otherwise  if it s a letter  alert  Error   If it is neither of these things  it returns false   HTML    lt form gt       lt input type  text  id  txt    gt   lt  form gt    JS    function a        a onkeypress   function e            if  e keyCode  gt   49  amp  amp  e keyCode  lt   57             else               if  e keyCode  gt   97  amp  amp  e keyCode  lt   122                    alert  Error                       return false                else return false                         txt      function   id        return document getElementById id       For a result  http   jsfiddle net uUc22   Mind you that the  keyCode result for  onkeypress   onkeydown  and  onkeyup differ from each other

[javascript] Allow only numeric value in textbox using Javascript

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