PHP Manual: Throw an exception into the generator

Description

public mixed Generator::throw ( Throwable $exception )

Throws an exception into the generator and resumes execution of the generator. The behavior will be the same as if the current yield expression was replaced with a throw $exception statement.

If the generator is already closed when this method is invoked, the exception will be thrown in the caller's context instead.

Parameters

exception: Exception to throw into the generator.

Return Values

Returns the yielded value.

Changelog

Version	Description
7.0.0	The `exception` parameter also accepts Throwable now.

Examples

Example #1 Throwing an exception into a generator


<?php
function gen() {
    echo "Foo\n";
    try {
        yield;
    } catch (Exception $e) {
        echo "Exception: {$e->getMessage()}\n";
    }
    echo "Bar\n";
}
 
$gen = gen();
$gen->rewind();
$gen->throw(new Exception('Test'));
?>

The above example will output:

Foo
Exception: Test
Bar