WP_Query count of different meta key values [duplicate]

Just loop over the posts and bump the count based on the value of ads_class:

$ads_1 =
$ads_2 =
$ads_3 = 0;

while ( $ads->have_post() ) {
    $ads->the_post();

    switch ( ( int ) get_post()->ads_class ) {
        case 1 :
            $ads_1++;
            break;
        case 2 :
            $ads_2++;
            break;
        case 3 :
            $ads_3++;
            break;
    }
}

$ads_1; // Number of "1" ads
$ads_2; // Number of "2" ads
$ads_3; // Number of "3" ads