simple example for exception

exception.php

class GPS_Coord extends Exception{}
class OutputCoord extends Exception {}
class ErorrNullable extends Exception{}

function drawPoint($point){
  if ($point!=0){
    if (is_string($point)){
      throw new GPS_Coord("Это строка!!", 200);
    }
    elseif($point > 500 && $point<10){
      throw new OutputCoord("point >500 Erorr input user!", 300);
    }
    else return $point;
  }
  else throw new ErorrNullable("Nullable number! Error",100);
}
try {
  echo drawPoint(3);
}catch(GPS_Coord $e){
  echo $e->getMessage();
}catch(OutputCoord $e){
  echo $e->getMessage();
}catch(ErorrNullable $e){
  echo $e->getMessage();
}