__toString Can Throw Exceptions

Until PHP 7.4, the magic method __toString() could not throw exception, in case of problem occurring during processing.

Since PHP 7.4, it is possible.

PHP code

<?php

class X {
    function __toString() {
        throw new \Exception('error'.__METHOD__);
    }
}

(string) new X;

?>

Before

PHP Fatal error:  Method X::__toString() must not throw an exception, caught Exception: errorX::__toString

Fatal error: Method X::__toString() must not throw an exception, caught Exception: errorX::__toString

After

PHP Fatal error:  Uncaught Exception: errorX::__toString

Fatal error: Uncaught Exception: errorX::__toString

PHP version change

This behavior changed in 7.4

Error Messages

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