Returns one of three values representing the sign of a number. Returns -1 if the number is negative, 1 if positive, 0 if 0.
         
         float sign( float number )
         
          number is the number whose sign you want to determine.
         
          
            Examples
            
 
             
            Returns -1.
            
 
             
            Returns 0.
            
 
             
            Returns 1.
            
 
             
            If Ball.translateX is 5, this returns 1.