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run code in 150+ php & hhvm versions
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<?php /** strrev function implementation taken from ext/standard/string.c PHP-5-5 branch http://lxr.php.net/xref/PHP_5_5/ext/standard/string.c#3165 // {{{ proto string strrev(string str) // Reverse a string PHP_FUNCTION(strrev) { char *str; char *e, *n, *p; int str_len; if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "s", &str, &str_len) == FAILURE) { return; } n = emalloc(str_len+1); p = n; e = str + str_len; while (--e>=str) { *p++ = *e; } *p = '\0'; RETVAL_STRINGL(n, str_len, 0); } // }}} */ // PHP Implementation function userland_strrev($string) { if (!is_string($string)) { return false; } $new_string = ""; $len = strlen($string); while (--$len > -1) { $new_string .= $string[$len]; } return $new_string; } $string = "Hello PHP!"; $c = 1000; $results = array(); $tests = array('strrev', 'userland_strrev'); foreach ($tests as $test) { for ($i = 0; $i < $c; $i++) { $t = microtime(true); $test($string); $results[$test][] = microtime(true) - $t; } $avg = array_sum($results[$test]) / count($results[$test]); printf("Average cost for function $test: %.6f ms\n", $avg); } // Without callable string resolution for ($i = 0; $i < $c; $i++) { $t = microtime(true); strrev($string); $results[$test][] = microtime(true) - $t; } $avg = array_sum($results[$test]) / count($results[$test]); printf("Average cost for function strrev: %.6f ms\n", $avg); for ($i = 0; $i < $c; $i++) { $t = microtime(true); userland_strrev($string); $results[$test][] = microtime(true) - $t; } $avg = array_sum($results[$test]) / count($results[$test]); printf("Average cost for function userland_strrev: %.6f ms\n", $avg);
Output for 5.4.15, 5.4.20, 5.4.27, 5.4.31 - 5.4.32, 5.5.24, 5.5.26 - 5.5.30, 5.5.32, 5.5.34 - 5.5.35, 5.6.10 - 5.6.13, 5.6.15, 5.6.18 - 5.6.20, 7.0.0, 7.0.4, 7.0.14 - 7.1.0
Average cost for function strrev: 0.000000 ms Average cost for function userland_strrev: 0.000001 ms Average cost for function strrev: 0.000001 ms Average cost for function userland_strrev: 0.000001 ms
Output for 7.0.1 - 7.0.2, 7.0.5 - 7.0.6
Average cost for function strrev: 0.000000 ms Average cost for function userland_strrev: 0.000001 ms Average cost for function strrev: 0.000000 ms Average cost for function userland_strrev: 0.000001 ms
Output for 7.0.3
Average cost for function strrev: 0.000000 ms Average cost for function userland_strrev: 0.000001 ms Average cost for function strrev: 0.000000 ms Average cost for function userland_strrev: 0.000000 ms
Output for 5.3.0 - 5.3.20, 5.3.22 - 5.4.14, 5.4.16 - 5.4.19, 5.4.21 - 5.4.26, 5.4.28 - 5.4.29, 5.4.34 - 5.4.35, 5.4.40, 5.4.43 - 5.4.45, 5.5.25, 5.5.31, 5.5.33, 5.6.8 - 5.6.9, 5.6.14, 5.6.16 - 5.6.17, 5.6.21 - 5.6.28
Average cost for function strrev: 0.000000 ms Average cost for function userland_strrev: 0.000002 ms Average cost for function strrev: 0.000001 ms Average cost for function userland_strrev: 0.000001 ms
Output for 5.1.0 - 5.1.3, 5.1.6 - 5.2.0, 5.4.38, 5.4.42
Average cost for function strrev: 0.000000 ms Average cost for function userland_strrev: 0.000003 ms Average cost for function strrev: 0.000002 ms Average cost for function userland_strrev: 0.000002 ms
Output for 5.0.2, 5.0.4 - 5.0.5, 5.2.2, 5.2.4 - 5.2.5, 5.4.41
Average cost for function strrev: 0.000001 ms Average cost for function userland_strrev: 0.000005 ms Average cost for function strrev: 0.000003 ms Average cost for function userland_strrev: 0.000003 ms
Output for 5.4.39
Average cost for function strrev: 0.000001 ms Average cost for function userland_strrev: 0.000003 ms Average cost for function strrev: 0.000001 ms Average cost for function userland_strrev: 0.000002 ms
Output for 5.2.1, 5.2.6 - 5.2.12, 5.2.14 - 5.2.17, 5.4.37
Average cost for function strrev: 0.000000 ms Average cost for function userland_strrev: 0.000002 ms Average cost for function strrev: 0.000001 ms Average cost for function userland_strrev: 0.000002 ms
Output for 5.4.36
Average cost for function strrev: 0.000001 ms Average cost for function userland_strrev: 0.000003 ms Average cost for function strrev: 0.000002 ms Average cost for function userland_strrev: 0.000002 ms
Output for 5.4.30
Average cost for function strrev: 0.000001 ms Average cost for function userland_strrev: 0.000004 ms Average cost for function strrev: 0.000002 ms Average cost for function userland_strrev: 0.000002 ms
Output for 5.3.21
Average cost for function strrev: 0.000001 ms Average cost for function userland_strrev: 0.000002 ms Average cost for function strrev: 0.000001 ms Average cost for function userland_strrev: 0.000001 ms
Output for 5.1.4 - 5.1.5, 5.2.13
Average cost for function strrev: 0.000000 ms Average cost for function userland_strrev: 0.000003 ms Average cost for function strrev: 0.000001 ms Average cost for function userland_strrev: 0.000002 ms
Output for 5.0.1, 5.0.3, 5.2.3
Average cost for function strrev: 0.000001 ms Average cost for function userland_strrev: 0.000004 ms Average cost for function strrev: 0.000002 ms Average cost for function userland_strrev: 0.000003 ms
Output for 4.3.10, 4.4.0 - 4.4.1, 4.4.4, 4.4.6 - 4.4.7, 5.0.0
Average cost for function strrev: 0.000001 ms Average cost for function userland_strrev: 0.000005 ms Average cost for function strrev: 0.000003 ms Average cost for function userland_strrev: 0.000004 ms
Output for 4.4.9
Average cost for function strrev: 0.000002 ms Average cost for function userland_strrev: 0.000009 ms Average cost for function strrev: 0.000005 ms Average cost for function userland_strrev: 0.000006 ms
Output for 4.3.2, 4.3.11, 4.4.2 - 4.4.3, 4.4.8
Average cost for function strrev: 0.000001 ms Average cost for function userland_strrev: 0.000006 ms Average cost for function strrev: 0.000003 ms Average cost for function userland_strrev: 0.000004 ms
Output for 4.4.5
Average cost for function strrev: 0.000001 ms Average cost for function userland_strrev: 0.000005 ms Average cost for function strrev: 0.000003 ms Average cost for function userland_strrev: 0.000005 ms
Output for 4.3.1, 4.3.5, 4.3.8 - 4.3.9
Average cost for function strrev: 0.000001 ms Average cost for function userland_strrev: 0.000006 ms Average cost for function strrev: 0.000004 ms Average cost for function userland_strrev: 0.000005 ms
Output for 4.3.6 - 4.3.7
Average cost for function strrev: 0.000001 ms Average cost for function userland_strrev: 0.000006 ms Average cost for function strrev: 0.000004 ms Average cost for function userland_strrev: 0.000004 ms
Output for 4.3.4
Average cost for function strrev: 0.000001 ms Average cost for function userland_strrev: 0.000007 ms Average cost for function strrev: 0.000004 ms Average cost for function userland_strrev: 0.000005 ms
Output for 4.3.3
Average cost for function strrev: 0.000002 ms Average cost for function userland_strrev: 0.000007 ms Average cost for function strrev: 0.000004 ms Average cost for function userland_strrev: 0.000005 ms
Output for 4.3.0
Average cost for function strrev: 0.000002 ms Average cost for function userland_strrev: 0.000008 ms Average cost for function strrev: 0.000005 ms Average cost for function userland_strrev: 0.000006 ms