1--TEST-- 2ReflectionEnum::getBackingType() 3--FILE-- 4<?php 5 6enum Enum_ {} 7enum IntEnum: int {} 8enum StringEnum: string {} 9 10function test(): string {} 11 12var_dump((new ReflectionEnum(Enum_::class))->getBackingType()); 13echo (new ReflectionEnum(IntEnum::class))->getBackingType() . "\n"; 14echo (new ReflectionEnum(StringEnum::class))->getBackingType() . "\n"; 15 16?> 17--EXPECT-- 18NULL 19int 20string 21