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<?php $a = 0x80; // 128 base 10 var_dump($a); var_dump(base_convert($a, 10, 2)); // not base_convert($a, 16, 2) $b = ~$a; // -128 - 1 == -129 base 10 var_dump($b); var_dump(base_convert($b, 10, 2), $b);// not base_convert($b, 16,2); can base_convert handle negative values? printf("%b", $b); echo "\n";
Output for 7.4.0 - 7.4.25, 7.4.27 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
int(128) string(8) "10000000" int(-129) Deprecated: Invalid characters passed for attempted conversion, these have been ignored in /in/FPYIC on line 7 string(8) "10000001" int(-129) 1111111111111111111111111111111111111111111111111111111101111111
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.26
int(128) string(8) "10000000" int(-129) string(8) "10000001" int(-129) 1111111111111111111111111111111111111111111111111111111101111111

preferences:
244.55 ms | 404 KiB | 456 Q