title: What does perl special variable $-[0] and $+[0] means
body: <p>I want to know the meaning of perl special variables <code>$-[0]</code> and <code>$+[0]</code></p>
  
  <p>I have googled and found that <code>$-</code> represent number of lines left on the page and <code>$+</code> represent the last bracket matched by the last search pattern.</p>
  
  <p>But my question is what <code>$-[0]</code> and <code>$+[0]</code> means in context of regular expressions.</p>
  
  <p>Let me know if code sample is required.</p>