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<?php $array = [ [1 => 2], [1 => 2], [2 => 1], [3 => 1], ]; $result = []; foreach ($array as $row) { $k = key($row); if (!isset($ref[$k])) { $ref[$k] = 0; $result[][$k] =& $ref[$k]; } $ref[$k] += $row[$k]; } var_export($result);
Output for 8.1.32, 8.2.0 - 8.2.29, 8.3.0 - 8.3.28, 8.4.1 - 8.4.14, 8.4.16, 8.5.0 - 8.5.1
array ( 0 => array ( 1 => 4, ), 1 => array ( 2 => 1, ), 2 => array ( 3 => 1, ), )
Output for 8.4.15
/bin/php-8.4.15: /usr/lib/libm.so.6: version `GLIBC_2.38' not found (required by /bin/php-8.4.15) /bin/php-8.4.15: /usr/lib/libm.so.6: version `GLIBC_2.35' not found (required by /bin/php-8.4.15) /bin/php-8.4.15: /usr/lib/libc.so.6: version `GLIBC_2.34' not found (required by /bin/php-8.4.15) /bin/php-8.4.15: /usr/lib/libc.so.6: version `GLIBC_2.38' not found (required by /bin/php-8.4.15)
Process exited with code 1.
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73.95 ms | 407 KiB | 5 Q