How to force input to only allow Alpha Letters

Question

using jQuery here  however unable to prevent numbers from being typed into the input field  http   codepen io leongaban pen owbjg  Input   lt input type  text  name  field  maxlength  8      title  Only Letters      value  Type Letters Only      onkeydown  return alphaOnly event        onblur  if  this value         this value    Type Letters Only         onfocus  if  this value     Type Letters Only    this value          gt    jQuery  function alphaOnly event       alert event      var key     if  window event        key   window event key      else if  e        key   e which          var key   window event key    event key    alert key value     return   key  gt   65  amp  amp  key  lt   90      key  gt   95  amp  amp  key  lt   122         I ve seen plenty of examples here on how to restrict to only Numbers  and I m using the correct key codes  for a-z and A-Z  Do you see what I m doing wrong

User · Answer

Nice one-liner HTML only     lt input type  text  id  nameInput  onkeypress  return   event charCode  gt   65  amp  amp  event charCode  lt   90      event charCode  gt   97  amp  amp  event charCode  lt   122      event charCode    32    gt

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A lot of the other solutions that use keypress will not work on mobile  you need to use input   html   lt input type  text  id  name   data-value    autocomplete  off  spellcheck  true  placeholder  Type your name  autofocus   gt    jQuery      name   on  input   function         var cursor pos     this  getCursorPosition       if      a-zA-Z       test   this  val                   this  val   this  attr  data-value              this  setCursorPosition cursor pos - 1          return             this  attr  data-value     this  val          fn getCursorPosition   function         if this length    0  return -1     return   this  getSelectionStart       fn setCursorPosition   function position        if this lengh    0  return this     return   this  setSelection position  position      fn getSelectionStart   function      if this lengh    0  return -1   input   this 0    var pos   input value length   if  input createTextRange        var r   document selection createRange   duplicate       r moveEnd  character   input value length      if  r text             pos   input value length     pos   input value lastIndexOf r text      else if typeof input selectionStart    undefined     pos   input selectionStart   return pos     fn setSelection   function selectionStart  selectionEnd      if this lengh    0  return this   input   this 0    if input createTextRange        var range   input createTextRange       range collapse true      range moveEnd  character   selectionEnd      range moveStart  character   selectionStart      range select         else if  input setSelectionRange        input focus       input setSelectionRange selectionStart  selectionEnd        return this

User · Answer

lt input type  text  name  name  id  event  onkeydown  return alphaOnly event      required   gt    function alphaOnly event      var key   event keyCode  enter code here    return   key  gt   65  amp  amp  key  lt   90     key    8

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lt input type  text  name  field  maxlength  8      onkeypress  return onlyAlphabets event this      gt   function onlyAlphabets e  t                try                   if  window event                        var charCode   window event keyCode                                    else if  e                        var charCode   e which                                    else   return true                    if   charCode  gt  64  amp  amp  charCode  lt  91      charCode  gt  96  amp  amp  charCode  lt  123                       return true                  else                     return false                            catch  err                    alert err Description

User · Answer

If your form is PHP based  it would work this way within your  quot   lt  php  data   array  quot  code       onkeypress    gt   return   a-z 0-9  i test event key

User · Answer

On newer browsers  you can use    lt input type  text  name  country code       pattern   A-Za-z   title  Three letter country code  gt    You can use regular expressions to restrict the input fields

User · Answer

Short ONELINER    x000D   x000D   lt input onkeypress  return   a-z  i test event key    gt  x000D   x000D   x000D    For all unicode letters try this regexp    p L  u  but     this  - and here is working example

User · Answer

Rather than relying on key codes  which can be quite cumbersome  you can instead use regular expressions  By changing the pattern we can easily restrict the input to fit our needs  Note that this works with the keypress event and will allow the use of backspace  as in the accepted answer   It will not prevent users from pasting  illegal  chars    x000D   x000D  function testInput event    x000D     var value   String fromCharCode event which   x000D     var pattern   new RegExp   a-z         i   x000D     return pattern test value   x000D    x000D   x000D      my-field   bind  keypress   testInput   x000D   lt script src  https   ajax googleapis com ajax libs jquery 2 1 1 jquery min js  gt  lt  script gt  x000D   lt label gt  x000D     Test input  x000D      lt input id  my-field  type  text  gt  x000D   lt  label gt  x000D   x000D   x000D

User · Answer

The property event key gave me an undefined value  Instead  I used event keyCode   function alphaOnly event      var key   event keyCode    return   key  gt   65  amp  amp  key  lt   90     key    8        Note that the value of 8 is for the backspace key

[javascript] How to force input to only allow Alpha Letters?

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