3v4l.org

run code in 300+ PHP versions simultaneously
<?php // 元データを用意する $a[2]=10; $a[10]=2; $a[3]=30; $a[22]=20; $a[9]=4; $a[53]=29; //確認 echo ($a); //キーを保持してソート asort($a); //確認 print_r($a); //最初から 3 個を $b[] に代入 $i = 0; $b = array(); foreach ($a as $k=>$d){ $b[] = $k; if (3 <= ++$i){ break;} } //確認 print_r($b); ?>
Output for 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
Warning: Array to string conversion in /in/11pqS on line 10 ArrayArray ( [10] => 2 [9] => 4 [2] => 10 [22] => 20 [53] => 29 [3] => 30 ) Array ( [0] => 10 [1] => 9 [2] => 2 )
Output for 5.4.0 - 5.4.45, 5.5.0 - 5.5.36, 5.6.0 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.31, 7.4.0 - 7.4.33
Notice: Array to string conversion in /in/11pqS on line 10 ArrayArray ( [10] => 2 [9] => 4 [2] => 10 [22] => 20 [53] => 29 [3] => 30 ) Array ( [0] => 10 [1] => 9 [2] => 2 )
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, 7.3.32 - 7.3.33
ArrayArray ( [10] => 2 [9] => 4 [2] => 10 [22] => 20 [53] => 29 [3] => 30 ) Array ( [0] => 10 [1] => 9 [2] => 2 )
preferences:
248.71 ms | 403 KiB | 376 Q