title: Variable scope in Javascript for loop
body: <p>What's the difference between:</p>
  
  <pre><code>function bar()
  {
    for (x=0; x&lt; 100; x++) {}
  }
  </code></pre>
  
  <p>And</p>
  
  <pre><code>function bar()
  {
    var x;
    for (x=0; x&lt; 100; x++) {}
  }
  </code></pre>
  
  <p>If x wasn't declared outside of that function, and so it wasn't a global variable? I always wonder this because I generally don't declare throwaway variables which are used only in a loop, but I wonder if this might break comparability in a browser or such. </p>