title: Pass function parameters as part of instruction
body: <p>I would like to pass function parameters as parts of my function code.</p>
  
  <pre><code>function update(value, key) {
      $localStorage.key = value;
  }
  </code></pre>
  
  <p>If I call my function with, lets say :</p>
  
  <pre><code>update(20, age);
  </code></pre>
  
  <p>The value (20) will be correctly used, but the key will be treated as 'key' not as 'age', thus saving content in a wrong object reference.</p>
  
  <p>Any idea for a quick fix ?</p>