fn() => return 1, 'b' => fn() => return 1, ]; /* testStaticArrowFunction */ static fn ($a) => $a; /* testArrowFunctionReturnValue */ fn(): array => [a($a, $b)]; /* testArrowFunctionAsArgument */ $foo = foo( fn() => bar() ); /* testArrowFunctionWithArrayAsArgument */ $foo = foo( fn() => [$row[0], $row[3]] ); return 0;