RegEx for Javascript to allow only alphanumeric

Question

I need to find a reg ex that only allows alphanumeric. So far, everyone I try only works if the string is alphanumeric, meaning contains both a letter and a number. I just w

Answer 1

Question is old, but it's never too late to answer

$(document).ready(function() {
  //prevent paste
  var usern_paste = document.getElementById('yourid');
  usern_paste.onpaste = e => e.preventDefault();

  //prevent copy
  var usern_drop = document.getElementById('yourid');
  usern_drop.ondrop = e => e.preventDefault();
});

$('#yourid').keypress(function (e) {
  var regex = new RegExp("^[a-zA-Z0-9\s]");
  var str = String.fromCharCode(!e.charCode ? e.which : e.charCode);
  if (regex.test(str)) {
      return true;
  }
  e.preventDefault();
  return false;
});