wp-includes/class-wpdb.php:3105Retrieves one column from the database.
$querystring|nulloptionalnull$xintoptional0array public function get_col( $query = null, $x = 0 ) { if ( $query ) { if ( $this->check_current_query && $this->check_safe_collation( $query ) ) { $this->check_current_query = false; } $this->query( $query ); } $new_array = array(); // Extract the column values. if ( $this->last_result ) { for ( $i = 0, $j = count( $this->last_result ); $i < $j; $i++ ) { $new_array[ $i ] = $this->get_var( null, $x, $i ); } } return $new_array; }Introduced in 0.71. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/class-wpdb.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.