Poor mans Javascript console

Quick and dirty way of testing Javascript live on a website in browsers without Firebug:

<form onsubmit="try {
    $('output').innerHTML = $F('input') + ' => ' + eval($F('input'));
  } catch (e) {
    alert(e)
  }
  return false">
  <div id="output"></div>
  <input id="input" name="input" value="" on="" />
</form>

Requires Prototype, but could probably be rewritten as pure Javascript pretty easily. Could also be turned into a bookmarklet, I guess.

Comments and Trackbacks

Without prototype.js would be something like:

Btw. if you are using prototype.js, you should probably be using the Element#update(value) method instead of using innerHTML

var input = $('input');
$('output').update(input.value + '=> ' + eval(input.value));