php - Modify selector to only target a specific tag [wordpress] -

code below target anchor link in wordpress navigation menu have new attribute 'data-foo' value 'bar'. how can modified target menu specific class?

add_filter( 'walker_nav_menu_start_el', function( $item ) {     $parts = explode( '>', $item );    $out   = array ();         foreach ( $parts $i => $part )    {       if ( 0 === strpos( $part, '<a ' ) ) // start          $out[ $i ] = $part . ' data-foo="bar"';          else          $out[ $i ] = $part;    }     return join( '>', $out ); }); 

in code "walker_nav_menu_start_el" pre-defined "filter". can use $get_body_class(classname) apply filter elements class.

$class = $get_body_class('yourclassnamehere');  add_filter( $class, function( $item ) {     $parts = explode( '>', $item );    $out   = array ();         foreach ( $parts $i => $part )    {       if ( 0 === strpos( $part, '<a ' ) ) // start          $out[ $i ] = $part . ' data-foo="bar"';          else          $out[ $i ] = $part;    }     return join( '>', $out ); });