Change $search_columns type from array to string[].

[tmatsuur]

The type of $search_columns added in version 6.2 is 'array'.

	 *     @type array           $search_columns          Array of column names to be searched. Accepts 'post_title',
	 *                                                    'post_excerpt' and 'post_content'. Default empty array.

I think 'string[]' would be more appropriate for this 'array' to match other parameters.

	 *     @type string[]        $search_columns          Array of column names to be searched. Accepts 'post_title',
	 *                                                    'post_excerpt' and 'post_content'. Default empty array.

This parameter is also converted to an array if it is not an array.

$search_columns         = ! empty( $q['search_columns'] ) ? $q['search_columns'] : $default_search_columns;
if ( ! is_array( $search_columns ) ) {
	$search_columns = array( $search_columns );
}

In light of the above, "string|string[]" would be better than "string[]".

	 *     @type string|string[] $search_columns          A column name (string) or array of column names to be searched.
	 *                                                    Accepts 'post_title', 'post_excerpt' and 'post_content'.
	 *                                                    Default empty array.

[SergeyBiryukov]

Thanks for the ticket!

The search_columns parameter is already documented as string[] in WP_User_Query as of [49693], and in WP_Site_Query as of [51184], so it definitely makes sense for WP_Query too. Introduced in [55248].

To match the above two classes, I think string[] would be preferable here, rather than string|string[]. While a string can technically be passed too, we should encourage passing an array for consistency.

[SergeyBiryukov]

In 55597:

Docs: Use typed array notation for search_columns in WP_Query::parse_query().

Follow-up to [55248].

Props tmatsuur.
Fixes #57996.

[SergeyBiryukov]

Reopening for 6.2.1 consideration.

[tmatsuur]

Replying to SergeyBiryukov:

Reopening for 6.2.1 consideration.

Thanks @SergeyBiryukov

[SergeyBiryukov]

In 55640:

Docs: Use typed array notation for search_columns in WP_Query::parse_query().

Follow-up to [55248].

Props tmatsuur.
Merges [55597] to the 6.2 branch.
Fixes #57996.