wp-includes/class-wpdb.php:1307Escapes data. Works on arrays.
$datastring|arraystring|array public function _escape( $data ) { if ( is_array( $data ) ) { foreach ( $data as $k => $v ) { if ( is_array( $v ) ) { $data[ $k ] = $this->_escape( $v ); } else { $data[ $k ] = $this->_real_escape( $v ); } } } else { $data = $this->_real_escape( $data ); } return $data; }Introduced in 2.8.0. 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.