Two arrays in foreach loop

foreach operates on only one array at a time.

The way your array is structured, you can array_combine() them into an array of key-value pairs then foreach that single array:

foreach (array_combine($codes, $names) as $code => $name) {
    echo '<option value="' . $code . '">' . $name . '</option>';
}

Or as seen in the other answers, you can hardcode an associative array instead.

Use array_combine() to fuse the arrays together and iterate over the result.

$countries = array_combine($codes, $names);

array_map seems good for this too

$codes = array('tn','us','fr');
$names = array('Tunisia','United States','France');

array_map(function ($code, $name) {
    echo '<option value="' . $code . '">' . $name . '</option>';
}, $codes, $names);

Other benefits are:

• If one array is shorter than the other, the callback receive null values to fill in the gap.

• You can use more than 2 arrays to iterate through.

foreach( $codes as $code and $names as $name ) { }

That is not valid.

You probably want something like this...

foreach( $codes as $index => $code ) {
   echo '<option value="' . $code . '">' . $names[$index] . '</option>';
}

Alternatively, it'd be much easier to make the codes the key of your $names array...

$names = array(
   'tn' => 'Tunisia',
   'us' => 'United States',
   ...
);