Question

83

jQuery do not allow alphabets to be entered in input field

rated 0 times [ 89] [ 6] / answers: 1 / hits: 17811 / 9 Years ago, thu, september 10, 2015, 12:00:00

My requirement is to not allow user to type in any Alphabets. The below code allows 1 character to be entered even though I have provided the e.preventDefault() method on both keydown and keyup methods.

$(function() {

  // Regular Expression to Check for Alphabets.

  var regExp = new RegExp('[a-zA-Z]');



  $('#test').on('keydown keyup', function(e) {



    var value = $(this).val();



    // Do not allow alphabets to be entered.

    if (regExp.test(value)) {

      e.preventDefault();

      return false;

    }



  }); // End of 'keydown keyup' method.



}); // End of 'document ready'

<script src=https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js></script>



<input type=text id=test name=test />

What am I doing wrong? Is there some other way to get this done?

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sashacitlallik

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1 Year ago

answered 9 Years ago domeniccolti · Accepted Answer

Replace

var value = $(this).val();

by

var value = String.fromCharCode(e.which) || e.key;

After all, you need to check which key has been pressed before allowing a character to be typed into the field.

Also, make sure the backspace and delete buttons and arrow keys aren’t blocked!

$(function() {

  var regExp = /[a-z]/i;

  $('#test').on('keydown keyup', function(e) {

    var value = String.fromCharCode(e.which) || e.key;



    // No letters

    if (regExp.test(value)) {

      e.preventDefault();

      return false;

    }

  });

});

<script src=https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js></script>



<input type=text id=test name=test />

If your goal is to only accept numbers, dots and commas use this function instead:

$(function() {

  var regExp = /[0-9.,]/;

  $('#test').on('keydown keyup', function(e) {

    var value = String.fromCharCode(e.which) || e.key;

    console.log(e);

    // Only numbers, dots and commas

    if (!regExp.test(value)

      && e.which != 188 // ,

      && e.which != 190 // .

      && e.which != 8   // backspace

      && e.which != 46  // delete

      && (e.which < 37  // arrow keys

        || e.which > 40)) {

          e.preventDefault();

          return false;

    }

  });

});

<script src=https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js></script>



<input type=text id=test name=test />