<form>
  <select name="single">
    <option>Single</option>
    <option>Single2</option>
  </select>
 
  <br>
  <select name="multiple" multiple="multiple">
    <option selected="selected">Multiple</option>
    <option>Multiple2</option>
    <option selected="selected">Multiple3</option>
  </select>
 
  <br>
  <input type="checkbox" name="check" value="check1" id="ch1">
  <label for="ch1">check1</label>
  <input type="checkbox" name="check" value="check2" checked="checked" id="ch2">
  <label for="ch2">check2</label>
 
  <br>
  <input type="radio" name="radio" value="radio1" checked="checked" id="r1">
  <label for="r1">radio1</label>
  <input type="radio" name="radio" value="radio2" id="r2">
  <label for="r2">radio2</label>
</form>
 
<p><tt id="results"></tt></p>
body, select {
    font-size: 12px;
  }
  form {
    margin: 5px;
  }
  p {
    color: red;
    margin: 5px;
    font-size: 14px;
  }
  b {
    color: blue;
  }
function showValues() {
    var str = $( "form" ).serialize();
    $( "#results" ).text( str );
}

$( "input[type='checkbox'], input[type='radio']" ).on( "click", showValues );

$( "select" ).on( "change", showValues );

showValues();

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

  1. https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js