title: How does true/false work in PHP?
body: <p>I wonder how PHP handles <strong>true/false</strong> comparison internally. 
  I understand that true is defined as 1 and false is defined as 0. 
  When I do <code>if("a"){ echo "true";}</code> it echos "<strong>true</strong>". How does PHP recognize "a" as 1 ? </p>