Disable some characters from input field

Issue

I have found some instructions similar, but none helps, all of them are either for special chars or for digits.

I need to make user type only 1 , 2 , 3, 4, 5, N, O, A, B, C . all other characters should be restricted.

Any way I can make my own selection of restricted/allowed chars for inputs ?

• Not very familiar with javascript.

Solution

Try this

$(function(){
  $('#txt').keypress(function(e){
    if(e.which == 97 || e.which == 98 || e.which == 99 || e.which == 110 || e.which == 111 || e.which == 65 || e.which == 66 || e.which == 67 || e.which == 78 || e.which == 79 || e.which == 49 || e.which == 50 || e.which == 51 || e.which == 52 || e.which == 53){
    } else {
      return false;
    }
  });
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input type='text' id='txt' value='' onpaste="return false" />

Update 9th March 2018

$(function(){
  $('#txt').keypress(function(e){
    // allowed char: 1 , 2 , 3, 4, 5, N, O, A, B, C
    let allow_char = [97,98,99,110,111,65,66,67,78,79,49,50,51,52,53];
    if(allow_char.indexOf(e.which) !== -1 ){
      //do something
    }
    else{
      return false;
    }
  });
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input type='text' id='txt' value='' onpaste="return false" />

Update 25th November 2020

let textarea = document.getElementById('txt');

textarea.addEventListener('keydown', (e) => {
  if(['1','2','3','4','5', 'N', 'O', 'A', 'B', 'C'].indexOf(e.key) !== -1){
    // do something
  } else {
    e.preventDefault();
  }
});

CodePen Demo

Answered By - Pragnesh Chauhan