- Output for 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.33, 8.2.0 - 8.2.29, 8.3.0 - 8.3.26, 8.4.1 - 8.4.14
- Warning: preg_replace(): Compilation failed: invalid range in character class at offset 6 in /in/KICjT on line 3 NULL
- Output for 7.3.0 - 7.3.33
- string(5) "abcd_"
- Output for 7.1.0 - 7.1.33, 7.2.0 - 7.2.33
- Warning: preg_replace(): Compilation failed: invalid range in character class at offset 5 in /in/KICjT on line 3 NULL