title: When should you use single or double quotes in PHP?
body: <p>Forgive the bluntness of the question, but I've noticed really you can use either single or double quotes to begin with, along as you follow the suite throughout.</p>
  
  <p>Someone once told me to use double quotes when echoing, outputting or returning, and single quotes for everything else.</p>
  
  <p>But I'd like to know, is there a solid reason when to only use single quotes, or vice versa and not the other?</p>