3v4l.org

run code in 300+ PHP versions simultaneously
<?php function longest_palendrome($string) { $current = $longest = ''; foreach (str_split(strrev($string)) as $char) { if (strstr($string, $current . $char)) { $current .= $char; } elseif (!empty($current) && strlen($current) > strlen($longest)) { $longest = $current; $current = ''; } } return $longest; } echo longest_palendrome("i ama racecar ama aaaaaaaabbbbbbbbaaaaaaaa");

Here you find the average performance (time & memory) of each version. A grayed out version indicates it didn't complete successfully (based on exit-code).

VersionSystem time (s)User time (s)Memory (MiB)
8.3.60.0120.00318.19
8.3.50.0130.00517.34
8.3.40.0090.00618.75
8.3.30.0090.00618.59
8.3.20.0050.00218.82
8.3.10.0040.00418.82
8.3.00.0050.00319.38
8.2.180.0080.00816.63
8.2.170.0070.00722.96
8.2.160.0090.00618.80
8.2.150.0050.00324.18
8.2.140.0000.00824.66
8.2.130.0000.00726.16
8.2.120.0040.00419.66
8.2.110.0080.00322.25
8.2.100.0070.00417.84
8.2.90.0080.00017.75
8.2.80.0040.00417.97
8.2.70.0060.00317.38
8.2.60.0040.00418.05
8.2.50.0000.00818.07
8.2.40.0040.00419.47
8.2.30.0030.00617.81
8.2.20.0080.00317.62
8.2.10.0000.00717.68
8.2.00.0040.00417.79
8.1.280.0160.00025.92
8.1.270.0040.00423.99
8.1.260.0000.00726.35
8.1.250.0050.00328.09
8.1.240.0060.00322.53
8.1.230.0070.00419.08
8.1.220.0060.00317.74
8.1.210.0040.00418.77
8.1.200.0030.00617.35
8.1.190.0040.00417.13
8.1.180.0080.00018.10
8.1.170.0000.00818.95
8.1.160.0040.00418.94
8.1.150.0040.00418.63
8.1.140.0070.00017.46
8.1.130.0030.00317.45
8.1.120.0000.00717.49
8.1.110.0000.00717.46
8.1.100.0000.00717.48
8.1.90.0030.00317.31
8.1.80.0050.00217.52
8.1.70.0030.00317.41
8.1.60.0040.00417.63
8.1.50.0040.00417.54
8.1.40.0070.00317.60
8.1.30.0040.00417.65
8.1.20.0000.01017.58
8.1.10.0050.00217.51
8.1.00.0000.00817.31
8.0.300.0000.00818.77
8.0.290.0040.00716.75
8.0.280.0000.00718.43
8.0.270.0070.00017.34
8.0.260.0000.00616.80
8.0.250.0030.00516.97
8.0.240.0000.00716.96
8.0.230.0030.00616.84
8.0.220.0030.00316.93
8.0.210.0070.00016.86
8.0.200.0000.00616.83
8.0.190.0040.00316.88
8.0.180.0090.00316.93
8.0.170.0000.00916.94
8.0.160.0030.00316.89
8.0.150.0040.00416.72
8.0.140.0000.00716.81
8.0.130.0000.00513.36
8.0.120.0100.00016.88
8.0.110.0030.00516.77
8.0.100.0040.00416.75
8.0.90.0030.00316.94
8.0.80.0140.00716.91
8.0.70.0000.00716.95
8.0.60.0060.00316.91
8.0.50.0000.00816.79
8.0.30.0060.01217.11
8.0.20.0090.01017.14
8.0.10.0050.00216.95
8.0.00.0080.01616.67
7.4.330.0050.00012.93
7.4.320.0030.00316.57
7.4.300.0030.00316.59
7.4.290.0070.00316.60
7.4.280.0000.00816.55
7.4.270.0030.00716.64
7.4.260.0000.00613.25
7.4.250.0030.00616.51
7.4.240.0030.00316.57
7.4.230.0000.00716.61
7.4.220.0140.00716.53
7.4.210.0100.01016.53
7.4.200.0030.00316.69
7.4.190.0040.00416.75
7.4.160.0120.00616.55
7.4.150.0130.00416.62
7.4.140.0100.01317.86
7.4.130.0160.00616.50
7.4.120.0080.00816.46
7.4.110.0160.00416.38
7.4.100.0030.01316.70
7.4.90.0070.01116.39
7.4.80.0110.00919.39
7.4.70.0070.01016.43
7.4.60.0170.00016.48
7.4.50.0030.00616.69
7.4.40.0030.01316.53
7.4.30.0080.01016.41
7.4.00.0080.00914.85
7.3.330.0060.00013.22
7.3.320.0070.00013.19
7.3.310.0030.00316.37
7.3.300.0040.00416.46
7.3.290.0080.00616.38
7.3.280.0170.00316.34
7.3.270.0100.01016.58
7.3.260.0180.00316.36
7.3.240.0000.01616.34
7.3.230.0030.01716.49
7.3.210.0080.00816.38
7.3.200.0090.00916.39
7.3.190.0060.01216.22
7.3.180.0140.00516.72
7.3.170.0140.00316.53
7.3.160.0170.00316.37
7.3.120.0080.00514.82
7.3.110.0100.00014.84
7.3.100.0060.00914.88
7.3.90.0030.01314.89
7.3.80.0070.01115.02
7.3.70.0100.00314.62
7.3.60.0030.01214.64
7.3.50.0030.00714.61
7.3.40.0090.00614.59
7.3.30.0070.00714.73
7.3.20.0000.00916.64
7.3.10.0050.00816.69
7.3.00.0050.00916.68
7.2.330.0110.00816.82
7.2.320.0110.01116.68
7.2.310.0040.01316.80
7.2.300.0090.01116.70
7.2.290.0100.00616.84
7.2.250.0070.00714.93
7.2.240.0050.00815.19
7.2.230.0060.01315.21
7.2.220.0060.01214.89
7.2.210.0130.00315.24
7.2.200.0090.00615.15
7.2.190.0070.00714.82
7.2.180.0040.00815.09
7.2.170.0040.00815.05
7.2.130.0030.00616.77
7.2.120.0090.00616.82
7.2.110.0070.00717.04
7.2.100.0040.00917.02
7.2.90.0040.01117.09
7.2.80.0030.01016.84
7.2.70.0070.00716.59
7.2.60.0100.00717.05
7.2.50.0100.00017.02
7.2.40.0110.00417.04
7.2.30.0070.01117.04
7.2.20.0060.01216.95
7.2.10.0120.00616.97
7.2.00.0070.00818.12
7.1.330.0000.01215.62
7.1.320.0030.01415.61
7.1.310.0070.00716.07
7.1.300.0070.00715.84
7.1.290.0080.00415.91
7.1.280.0100.00315.71
7.1.270.0030.00515.66
7.1.260.0040.01115.78
7.1.250.0030.00715.93
7.1.100.0080.00318.40
7.1.70.0090.01217.34
7.1.60.0080.00417.29
7.1.50.0070.00417.17
7.1.00.0030.04322.37
7.0.200.0060.00916.86
7.0.140.0100.06722.04
7.0.120.0000.06022.17
7.0.60.0070.08020.07
7.0.50.0100.07317.95
7.0.40.0170.07720.23
7.0.30.0130.04320.06
7.0.20.0300.08720.21
7.0.10.0300.07320.12
7.0.00.0170.08020.07
5.6.280.0030.07320.93
5.6.210.0130.03020.47
5.6.200.0030.08318.18
5.6.190.0100.07020.63
5.6.180.0230.07020.42
5.6.170.0200.04720.71
5.6.160.0030.07720.55
5.6.150.0070.05018.15
5.6.140.0070.07018.16
5.6.130.0070.04718.12
5.6.120.0030.06320.98
5.6.110.0000.06321.15
5.6.100.0170.07721.02
5.6.90.0070.04720.98
5.6.80.0170.07020.38
5.5.350.0230.07320.46
5.5.340.0130.07717.96
5.5.330.0030.06720.31
5.5.320.0470.06020.44
5.5.310.0400.07020.41
5.5.300.0070.08318.08
5.5.290.0100.05717.96
5.5.280.0030.05720.98
5.5.270.0070.07720.93
5.5.260.0000.07720.89
5.5.250.0070.06720.49
5.5.240.0070.08320.19
5.4.450.0000.04319.20
5.4.440.0070.03719.18
5.4.430.0000.04019.57
5.4.420.0030.03719.25
5.4.410.0030.03719.25
5.4.400.0100.03019.12
5.4.390.0000.04018.94
5.4.380.0030.03718.95
5.4.370.0070.07019.16
5.4.360.0070.03719.14
5.4.350.0100.05018.87
5.4.340.0070.07018.84
5.4.320.0070.07719.08
5.4.310.0070.07719.16
5.4.300.0170.07019.24
5.4.290.0100.07019.11
5.4.280.0130.06018.92
5.4.270.0070.04019.00
5.4.260.0030.04319.07
5.4.250.0030.04019.07
5.4.240.0100.03719.13
5.4.230.0070.07019.00
5.4.220.0070.06719.23
5.4.210.0070.03718.98
5.4.200.0070.03319.07
5.4.190.0100.04019.13
5.4.180.0000.08019.23
5.4.170.0070.04319.04
5.4.160.0070.07018.84
5.4.150.0070.03719.13
5.4.140.0000.04716.40
5.4.130.0100.05716.52
5.4.120.0100.04716.43
5.4.110.0070.07316.30
5.4.100.0070.06716.30
5.4.90.0100.06716.45
5.4.80.0030.07716.39
5.4.70.0070.07016.32
5.4.60.0100.06016.35
5.4.50.0030.08016.36
5.4.40.0130.07016.50
5.4.30.0030.05316.46
5.4.20.0100.03716.36
5.4.10.0100.06716.42
5.4.00.0130.06315.76
5.3.290.0030.08314.70
5.3.280.0170.06714.64
5.3.270.0030.08014.63
5.3.260.0100.04014.64
5.3.250.0030.03714.64
5.3.240.0000.06714.61
5.3.230.0070.07014.65
5.3.220.0130.06314.71
5.3.210.0070.07714.60
5.3.200.0030.08014.58
5.3.190.0100.07314.58
5.3.180.0100.07314.62
5.3.170.0070.07314.61
5.3.160.0070.04714.61
5.3.150.0100.07014.61
5.3.140.0070.04714.61
5.3.130.0030.08014.55
5.3.120.0070.06314.56
5.3.110.0000.05014.59
5.3.100.0100.07313.96
5.3.90.0200.05014.07
5.3.80.0070.07314.16
5.3.70.0070.08314.02
5.3.60.0130.06714.05
5.3.50.0000.06713.94
5.3.40.0100.06713.95
5.3.30.0070.06313.98
5.3.20.0100.03713.61
5.3.10.0030.04013.67
5.3.00.0030.07313.60
5.2.170.0100.03011.09
5.2.160.0030.06011.11
5.2.150.0070.05711.19
5.2.140.0100.04711.03
5.2.130.0130.04011.15
5.2.120.0030.04011.11
5.2.110.0000.04011.25
5.2.100.0070.04311.02
5.2.90.0030.06311.11
5.2.80.0030.04011.13
5.2.70.0030.03011.05
5.2.60.0100.02311.11
5.2.50.0070.02711.05
5.2.40.0030.06010.88
5.2.30.0130.04711.03
5.2.20.0000.03310.95
5.2.10.0000.03010.75
5.2.00.0030.04310.75
5.1.60.0070.02710.14
5.1.50.0030.0509.99
5.1.40.0000.0609.89
5.1.30.0030.04010.41
5.1.20.0000.04710.39
5.1.10.0000.04310.23
5.1.00.0100.03010.21
5.0.50.0030.0438.59
5.0.40.0000.0338.46
5.0.30.0030.0678.20
5.0.20.0070.0338.16
5.0.10.0030.0238.15
5.0.00.0000.0708.19
4.4.90.0030.0137.88
4.4.80.0030.0137.88
4.4.70.0000.0407.88
4.4.60.0000.0177.88
4.4.50.0030.0237.88
4.4.40.0000.0577.88
4.4.30.0070.0307.88
4.4.20.0000.0377.88
4.4.10.0070.0337.88
4.4.00.0000.0477.88
4.3.110.0030.0337.88
4.3.100.0000.0337.88
4.3.90.0000.0277.88
4.3.80.0030.0437.88
4.3.70.0030.0307.88
4.3.60.0030.0377.88
4.3.50.0030.0337.88
4.3.40.0000.0407.88
4.3.30.0000.0307.88
4.3.20.0030.0207.88
4.3.10.0070.0277.88
4.3.00.0000.0307.88

preferences:
56.16 ms | 401 KiB | 5 Q