AS3 Trace statement is used to output actionscript 3 to the console. This can be very handy in debugging, when writing code, an example could be to check whether something is being parsed.

AS3 Trace Example

var output:Number = 4 + 3;
trace( "This number is seven : " + output );

//Should output
//This number is seven : 7

AS3 Trace Loop Example

if( var i:int = 0; i < 10; i++)
{
  trace(i);
}
//This should output the numbers 1 to 10
Related Articles Link
Republicofcode AS3 Trace http://www.republicofcode.com/tutorials/flash/as3trace/