您甚至不需要将它们放入数组中-应该可以使用以下方法：

// set code checks back to 0
$code_checks = 0;

$args = array( 
    'post_type' => 'hunters',
    'posts_per_page' => -1, 
    'orderby' => 'title', 
    'order' => 'ASC' ,
    'meta_key'=> 'full_ name',
    'meta_value'=> $email,
    'meta_key'=> 'w3w_location_hit',
    'meta_value'=> $w3w
);

$loop = new WP_Query( $args );
    
    while ( $loop->have_posts() ) {
        
        // get code checks in this iteration
        $number = get_field('code_checks');
        
        // add this iteration to total
        $code_checks = $code_checks + $number;
        
    }
    
    // echo total
    echo 'There were ' . $code_checks . ' checks made in total';

/* Restore original Post Data */
wp_reset_postdata();