title: Pros and cons of assigning new variables vs. re-using exisiting ones
body: <p>First, I apologize if this just a coding style issue. I'm wondering about the pros and cons of assign a new variable for each property or function to just to re-assign an existing variable. This is assuming you don't need access to the variable beyond the scope.</p>
  
  <p>Here's what I mean (noting that the names <code>$var0,...</code> are just for simplicity),
  Option#1:</p>
  
  <pre><code>$var0= array('hello', 'world');
  $var1="hello world";
  $var2=//some crazy large database query result
  $var3=//some complicated function()
  </code></pre>
  
  <p>vs.
  Option#2:</p>
  
  <pre><code>$var0= array('hello', 'world');
  $var0="hello world";
  $var0=//some crazy large database query result
  $var0=//some complicated function()
  </code></pre>
  
  <ol>
  <li>Does it depend on the memory size of the existing variable? I.e., is re-assigning memory more computationally expensive that assigning a new variable?</li>
  <li>Is this always a scope issue, meaning you should use Option#2 only if you don't need each of the variable values outside the scope shown here?</li>
  <li>Does it depend on what each variable value is? Does re-assigning to different data types have different costs associated with it?</li>
  </ol>