3v4l.org

run code in 300+ PHP versions simultaneously
<?php for ($x = 1; $x <= 100; $x++) { $root = sqrt($x); $state = ($root == floor($root)) ? 'open' : 'closed'; echo "Door $x: $state\n"; }
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 - 8.1.28, 8.2.0 - 8.2.19, 8.3.0 - 8.3.7
Door 1: open Door 2: closed Door 3: closed Door 4: open Door 5: closed Door 6: closed Door 7: closed Door 8: closed Door 9: open Door 10: closed Door 11: closed Door 12: closed Door 13: closed Door 14: closed Door 15: closed Door 16: open Door 17: closed Door 18: closed Door 19: closed Door 20: closed Door 21: closed Door 22: closed Door 23: closed Door 24: closed Door 25: open Door 26: closed Door 27: closed Door 28: closed Door 29: closed Door 30: closed Door 31: closed Door 32: closed Door 33: closed Door 34: closed Door 35: closed Door 36: open Door 37: closed Door 38: closed Door 39: closed Door 40: closed Door 41: closed Door 42: closed Door 43: closed Door 44: closed Door 45: closed Door 46: closed Door 47: closed Door 48: closed Door 49: open Door 50: closed Door 51: closed Door 52: closed Door 53: closed Door 54: closed Door 55: closed Door 56: closed Door 57: closed Door 58: closed Door 59: closed Door 60: closed Door 61: closed Door 62: closed Door 63: closed Door 64: open Door 65: closed Door 66: closed Door 67: closed Door 68: closed Door 69: closed Door 70: closed Door 71: closed Door 72: closed Door 73: closed Door 74: closed Door 75: closed Door 76: closed Door 77: closed Door 78: closed Door 79: closed Door 80: closed Door 81: open Door 82: closed Door 83: closed Door 84: closed Door 85: closed Door 86: closed Door 87: closed Door 88: closed Door 89: closed Door 90: closed Door 91: closed Door 92: closed Door 93: closed Door 94: closed Door 95: closed Door 96: closed Door 97: closed Door 98: closed Door 99: closed Door 100: open

preferences:
155.03 ms | 407 KiB | 300 Q