title: single, double and precision
body: <p>I know that storing single value (or double) can not be very precise. so storing for example 125.12 can result in 125.1200074788. now in delphi their is some usefull function like samevalue or comparevalue that take an epsilon as param and say that 125.1200074788 or for exemple 125.1200087952 is equal.</p>
  
  <p>but i often see in code stuff like : if aSingleVar = 0 then ... and this in fact as i see always work. why ? why storing for exemple 0 in a single var keep the exact value ?</p>