try catch throw

try {
  var_dump('abc');
  throw new Exception('abc');
  var_dump('abc-1');
}
catch(Exception $e){
  var_dump('catch');
}
var_dump('below try catch');
----------------
string(3) "abc"
string(5) "catch"
string(15) "below try catch"
---
是正常输出的， 在try里面的throw直接跳到exception, 并且exceptlin里面必须加参数， 然后跳出catch，继续运行，
但如果throw不在try里面，则直接报错了
  var_dump('abc');
  throw new Exception('abc');
  var_dump('abc-1');
var_dump('below try catch');

-------------------------------------------------------------------------------------------

string(3) "abc"

Fatal error: Uncaught Exception: abc in /box/script.php:4
Stack trace:
#0 {main}
  thrown in /box/script.php on line 4

Exited with error status 255