Create an hierarchaly ordere array of terms

term hierarchy

// Hierarchaly ordered array of terms
function sort_terms_hierarchicaly( Array &$cats, Array &$into, $parentId = 0 ) {
	foreach ( $cats as $i => $cat ) {
		if ( $cat->parent == $parentId ) {
			$into[$cat->term_id] = $cat;
			unset( $cats[$i] );
		}
	}

	foreach ( $into as $topCat ) {
		$topCat->children = array();
		sort_terms_hierarchicaly( $cats, $topCat->children, $topCat->term_id );
	}
}
/***
$categories = get_terms('my_taxonomy_name', array('hide_empty' => false));
$categoryHierarchy = array();
sort_terms_hierarchicaly($categories, $categoryHierarchy);

var_dump($categoryHierarchy);
***/