Sorting by meta query alias keys

If you’re familiar with WP_Query, you’ve probably already used the meta_query syntax:

How to use custom PHP code?
PHP code can be added to your (child) theme's functions.php file. Alternatively, you can use the Custom Hooks add-on, or a code snippets plugin. More info
$args = [
    'post_type' => 'cars',
    'post_status' => 'publish',
    'meta_query' => [
        [
            'key' => 'featured_sales',
            'compare' => 'EXISTS'
        ]
    ]
];

But did you know that you can give each meta_query segment a unique key:

How to use custom PHP code?
PHP code can be added to your (child) theme's functions.php file. Alternatively, you can use the Custom Hooks add-on, or a code snippets plugin. More info
$args = [
    'post_type' => 'cars',
    'post_status' => 'publish',
    'meta_query' => [
        'is_featured_sales' => [
            'key' => 'featured_sales',
            'compare' => 'EXISTS'
        ]
    ]
];

And use this key within the orderby clause?

How to use custom PHP code?
PHP code can be added to your (child) theme's functions.php file. Alternatively, you can use the Custom Hooks add-on, or a code snippets plugin. More info
$args = [
    'post_type' => 'cars',
    'post_status' => 'publish',
    'meta_query' => [
        'is_featured_sales' => [
            'key' => 'featured_sales',
            'compare' => 'EXISTS'
        ]
    ],
    'orderby' => [ 'is_featured_sales' => 'DESC' ]
];

This handy feature was added in WordPress 4.2.