Can someone explain this???

[rapidcarbon]

onClipEvent (enterFrame){
  value = substring(this.myInput, 1, 4);
  trace ("value: "+ value);
}

and

onClipEvent (enterFrame){
  value = substring(this.myInput, 0, 4);
  trace ("value: "+ value);
}

are the same? I got the same result for both codes.

please note the different: 1 and 0