title: Where is the difference between writing 0.1 and 0.1f in objective-c?
body: <p>Sometimes I write a float like:</p>
  
  <p>0.1</p>
  
  <p>and sometimes I add an f, like:</p>
  
  <p>0.1f</p>
  
  <p>It often seems that both ways work. I picked the f up from some sample code. But what's that actually good for? I'm sure it means "float", but do I really need that?</p>