3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = array( array( 0 => array( 'one' => 1, 'two' => 2 ), 1 => array( 'three' => 1 ) ), array( 0 => array( 'one1' => 1, 'two1' => 2 ), 1 => array( 'three1' => 1 ) ) ); foreach($a as $child){ $flatten[] = array_merge(...$child); } print_r($flatten);
Output for 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 - 8.1.33, 8.2.0 - 8.2.29, 8.3.0 - 8.3.28, 8.4.1 - 8.4.14, 8.5.0 - 8.5.1
Array ( [0] => Array ( [one] => 1 [two] => 2 [three] => 1 ) [1] => Array ( [one1] => 1 [two1] => 2 [three1] => 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.

preferences:
207.49 ms | 407 KiB | 5 Q