3v4l.org

run code in 300+ PHP versions simultaneously
<?php function toggleDigitAlpha ($val) { $lookup = range("A", "Z"); if (ctype_alpha((string)$val)) { $lookup = array_flip($lookup); } return strtr($val, $lookup); } $string = "ABYZ"; echo "$string\n"; $string = toggleDigitAlpha($string); echo "$string\n"; $string = toggleDigitAlpha($string); echo "$string\n"; $string = toggleDigitAlpha($string); echo "$string";
Output for 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.34, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.34, 8.2.0 - 8.2.30, 8.3.0 - 8.3.30, 8.4.1 - 8.4.18, 8.5.0 - 8.5.3
ABYZ 012425 AMEZ 012425
preferences:
86.56 ms | 1989 KiB | 4 Q