The throw Command

The throw command is used for explicitly throwing an exception in PHP. It accepts one parameter - an exception object, which must be an instance of a class inherited from the base Exception class. When this function is called, the execution of the current code immediately stops, and PHP attempts to find a corresponding catch block to handle the exception.

Syntax

phpthrow new ExceptionClass(message, code, previous);

Example

A simple example of generating an exception:

php<?php
  $age = -5;
  if ($age < 0) {
    throw new Exception('Age cannot be negative');
  }
?>

Code execution result:

phpFatal error: Uncaught Exception: Age cannot be negative

Example

Example with exception handling:

php<?php
  try {
    $res = 10 / 0;
    if (is_infinite($res)) {
      throw new Exception('Division by zero');
    }
  } catch (Exception $e) {
    echo 'Error: ' . $e->getMessage();
  }
?>

Code execution result:

php'Error: Division by zero'

Example

Using a custom exception:

php<?php
  class MyCustomException extends Exception {}
  
  try {
    throw new MyCustomException('Custom error message');
  } catch (MyCustomException $e) {
    echo 'Custom error caught: ' . $e->getMessage();
  }
?>

Code execution result:

php'Custom error caught: Custom error message'

See Also