limit input text or number length

Change class name on click in jQuery

HTML

<input type="text" id="numberInput">

JavaScript

$.fn.NumberLenghtLimit = function(numLimit) {
  var currentEle = $(this);

  function main() {
    var getCurrentVal = currentEle.val();
    if (getCurrentVal.length > numLimit) {
      	currentEle.val(getCurrentVal.substring(0, numLimit));
    }
  }
  $(document).on("keyup", currentEle, main);
}

// call method here with number limit
$("#numberInput").NumberLenghtLimit(4);