title: PHP: What do the curly braces in $variable{0} do?
body: <p>I was going through a codebase and came across a line I had a question about.  It's something I haven't seen before and I was wondering if someone could explain it for me.  Here's the code:</p>
  
  <pre><code>$variableName = $array[1];
  $variableName{0} = strtolower($variableName{0});
  $this-&gt;property = $variableName;
  </code></pre>
  
  <p>What are the curly braces being used for?  I've used curly braces to define variables as variable names before, but is this the same thing?  I can't seem to find any resources online that explain it, but I'm not sure if I'm searching for the right thing.</p>