php，从另外2创建1个数组[关闭]

Question

I have two arrays like this:

$a1 = ['A','B'];
$a2 = ['1','2'];

I need to have this new one (with the _ between the values):

$a3 = ['A_1','B_2'];

I know isn't difficult, but I'm pretty stucked, using array_combine and stuff.

Any help? thanks

Answer 1

This should solve your problem

for($i=0;$i<count($a1);$i++) {
    $a3[] = $a1[$i] . '_' . $a2[$i];
}
print_r($a3);