title: Changing the sign of a number in PHP?
body: <p>I have a few floats:</p>
  
  <pre><code>-4.50
  +6.25
  -8.00
  -1.75
  </code></pre>
  
  <p>How can I change all these to negative floats so they become:</p>
  
  <pre><code>-4.50
  -6.25
  -8.00
  -1.75
  </code></pre>
  
  <p>Also I need a way to do the reverse</p>
  
  <p>If the float is a negative, make it a positive.</p>