Default to array when value is null or false

Question

I'm working with ACF in WP which provides a get_field() function. The function can return an array of values, null or false. When the result of the function doesn't contain an array of values I want to default to an empty array.

This is how I do it at the moment but would like to know if there's a neater way to accomplish the same thing.

// can these lines be combined into one without multiple function calls?
$field = get_field('mobile_menu', 'option');
$field = $field ? $field : [];

return collect($field); // other processing

Answer 1

Shake Rattle and Roll ?:

The ternary short cut ?: , A.K.A. "the Elvis operator" has been available since PHP 5.3.

It could be used to simplify that second line:

$field = $field ? $field : [];

to:

$field = $field ?: [];

That could be used on the line where get_field() is called:

$field = get_field('mobile_menu', 'option') ?: [];

which would allow for the elimination of the second line.

At that point $field is a single-use variable and can be eliminated:

return collect(get_field('mobile_menu', 'option') ?: []);