- array_slice: documentation ( source)
- var_export: documentation ( source)
<?php
$a1 = ['a' => 0, 'c' => 1, 'e' => 2];
$a2 = ['b' => 3, 'd' => 4, 'f' => 5];
$result = [];
for ($i = 0, $count = count($a1); $i < $count; ++$i) {
$result += array_slice($a1, $i, 1)
+ array_slice($a2, $i, 1);
}
var_export($result);