en la LIGA ahi te dice que es lo mismo que el if
  
 The following example shows a conditional statement written in shorthand:  
Código:
 var timecode:String = (new Date().getHours() < 11) ? "AM" : "PM"; 
trace(timecode); 
The same conditional statement could also be written in longhand, as shown in the following example:
if (new Date().getHours() < 11) { 
 var timecode:String = "AM"; 
} else { 
 var timecode:String = "PM"; 
} trace(timecode);