title: change current TextArea value without assign a new one?
body: <p>When I press "A" to add a character to a value of the TextArea, how does the value change?
  does the browser do something like this:</p>
  
  <pre><code>texarea.value+="A";
  //same as:
  texarea.value=texarea.value+"A";
  </code></pre>
  
  <p>?</p>
  
  <p>I would like to change that value dynamicaly and notify the textarea about the change without assign a new one, because I think that assingment is not very perfomant if the value takes a lot of memory.
  Is there a way to do this?</p>