Retrieves the terms in a given taxonomy or list of taxonomies.

You can fully inject any customizations to the query before it is sent, as well as control the output with a filter.

The return type varies depending on the value passed to $args['fields']. See WP_Term_Query::get_terms() for details. In all cases, a WP_Error object will be returned if an invalid taxonomy is requested.

The ‘get_terms’ filter will be called when the cache has the term and will pass the found term along with the array of $taxonomies and array of $args.
This filter is also called before the array of terms is passed and will pass the array of terms, along with the $taxonomies and $args.

The ‘list_terms_exclusions’ filter passes the compiled exclusions along with the $args.

The ‘get_terms_orderby’ filter passes the ORDER BY clause for the query along with the $args array.

Prior to 4.5.0, the first parameter of get_terms() was a taxonomy or list of taxonomies:

$terms = get_terms( 'post_tag', array(
    'hide_empty' => false,
) );

Since 4.5.0, taxonomies should be passed via the ‘taxonomy’ argument in the $args array:

$terms = get_terms( array(
    'taxonomy' => 'post_tag',
    'hide_empty' => false,
) );

$args array|string Optional

Array or string of arguments. See WP_Term_Query::__construct() for information on accepted arguments.

More Arguments from WP_Term_Query::__construct( ... $query )

Array or query string of term query parameters.

• taxonomystring|string[]
  Taxonomy name, or array of taxonomy names, to which results should be limited.
• object_idsint|int[]
  Object ID, or array of object IDs. Results will be limited to terms associated with these objects.
• orderbystring
  Field(s) to order terms by. Accepts:
  

  • Term fields ('name', 'slug', 'term_group', 'term_id', 'id', 'description', 'parent', 'term_order'). Unless $object_ids is not empty, 'term_order' is treated the same as 'term_id'.
  • 'count' to use the number of objects associated with the term.
  • 'include' to match the 'order' of the $include param.
  • 'slug__in' to match the 'order' of the $slug param.
  • 'meta_value'
  • 'meta_value_num'.
  • The value of $meta_key.
  • The array keys of $meta_query.
  • 'none' to omit the ORDER BY clause.

  Default 'name'.
• orderstring
  Whether to order terms in ascending or descending order.
  Accepts 'ASC' (ascending) or 'DESC' (descending).
  Default 'ASC'.
• hide_emptybool|int
  Whether to hide terms not assigned to any posts. Accepts 1|true or 0|false. Default 1|true.
• includeint[]|string
  Array or comma/space-separated string of term IDs to include.
  Default empty array.
• excludeint[]|string
  Array or comma/space-separated string of term IDs to exclude.
  If $include is non-empty, $exclude is ignored.
  Default empty array.
• exclude_treeint[]|string
  Array or comma/space-separated string of term IDs to exclude along with all of their descendant terms. If $include is non-empty, $exclude_tree is ignored. Default empty array.
• numberint|string
  Maximum number of terms to return. Accepts ''|0 (all) or any positive number. Default ''|0 (all). Note that $number may not return accurate results when coupled with $object_ids.
  See #41796 for details.
• offsetint
  The number by which to offset the terms query.
• fieldsstring
  Term fields to query for. Accepts:
  

  • 'all' Returns an array of complete term objects (WP_Term[]).
  • 'all_with_object_id' Returns an array of term objects with the 'object_id' param (WP_Term[]). Works only when the $object_ids parameter is populated.
  • 'ids' Returns an array of term IDs (int[]).
  • 'tt_ids' Returns an array of term taxonomy IDs (int[]).
  • 'names' Returns an array of term names (string[]).
  • 'slugs' Returns an array of term slugs (string[]).
  • 'count' Returns the number of matching terms (int).
  • 'id=>parent' Returns an associative array of parent term IDs, keyed by term ID (int[]).
  • 'id=>name' Returns an associative array of term names, keyed by term ID (string[]).
  • 'id=>slug' Returns an associative array of term slugs, keyed by term ID (string[]).

  Default 'all'.
• countbool
  Whether to return a term count. If true, will take precedence over $fields. Default false.
• namestring|string[]
  Name or array of names to return term(s) for.
  
• slugstring|string[]
  Slug or array of slugs to return term(s) for.
  
• term_taxonomy_idint|int[]
  Term taxonomy ID, or array of term taxonomy IDs, to match when querying terms.
• hierarchicalbool
  Whether to include terms that have non-empty descendants (even if $hide_empty is set to true). Default true.
• searchstring
  Search criteria to match terms. Will be SQL-formatted with wildcards before and after.
• name__likestring
  Retrieve terms with criteria by which a term is LIKE $name__like.
• description__likestring
  Retrieve terms where the description is LIKE $description__like.
• pad_countsbool
  Whether to pad the quantity of a term's children in the quantity of each term's "count" object variable. Default false.
• getstring
  Whether to return terms regardless of ancestry or whether the terms are empty. Accepts 'all' or '' (disabled). Default ''.
• child_ofint
  Term ID to retrieve child terms of. If multiple taxonomies are passed, $child_of is ignored. Default 0.
• parentint
  Parent term ID to retrieve direct-child terms of.
  
• childlessbool
  True to limit results to terms that have no children.
  This parameter has no effect on non-hierarchical taxonomies.
  Default false.
• cache_domainstring
  Unique cache key to be produced when this query is stored in an object cache. Default 'core'.
• update_term_meta_cachebool
  Whether to prime meta caches for matched terms. Default true.
• meta_keystring|string[]
  Meta key or keys to filter by.
• meta_valuestring|string[]
  Meta value or values to filter by.
• meta_comparestring
  MySQL operator used for comparing the meta value.
  See WP_Meta_Query::__construct() for accepted values and default value.
• meta_compare_keystring
  MySQL operator used for comparing the meta key.
  See WP_Meta_Query::__construct() for accepted values and default value.
• meta_typestring
  MySQL data type that the meta_value column will be CAST to for comparisons.
  See WP_Meta_Query::__construct() for accepted values and default value.
• meta_type_keystring
  MySQL data type that the meta_key column will be CAST to for comparisons.
  See WP_Meta_Query::__construct() for accepted values and default value.
• meta_queryarray
  An associative array of WP_Meta_Query arguments.
  See WP_Meta_Query::__construct() for accepted values.

Default: array()

$deprecated array|string Optional

Argument array, when using the legacy function parameter format.
If present, this parameter will be interpreted as $args, and the first function parameter will be parsed as a taxonomy or array of taxonomies.

Default: ''

WP_Term[]|int[]|string[]|string|WP_Error Array of terms, a count thereof as a numeric string, or WP_Error if any of the taxonomies do not exist.
See the function description for more information.

File: wp-includes/taxonomy.php. View all references

function get_terms( $args = array(), $deprecated = '' ) {
	$term_query = new WP_Term_Query();

	$defaults = array(
		'suppress_filter' => false,
	);

	/*
	 * Legacy argument format ($taxonomy, $args) takes precedence.
	 *
	 * We detect legacy argument format by checking if
	 * (a) a second non-empty parameter is passed, or
	 * (b) the first parameter shares no keys with the default array (ie, it's a list of taxonomies)
	 */
	$_args          = wp_parse_args( $args );
	$key_intersect  = array_intersect_key( $term_query->query_var_defaults, (array) $_args );
	$do_legacy_args = $deprecated || empty( $key_intersect );

	if ( $do_legacy_args ) {
		$taxonomies       = (array) $args;
		$args             = wp_parse_args( $deprecated, $defaults );
		$args['taxonomy'] = $taxonomies;
	} else {
		$args = wp_parse_args( $args, $defaults );
		if ( isset( $args['taxonomy'] ) && null !== $args['taxonomy'] ) {
			$args['taxonomy'] = (array) $args['taxonomy'];
		}
	}

	if ( ! empty( $args['taxonomy'] ) ) {
		foreach ( $args['taxonomy'] as $taxonomy ) {
			if ( ! taxonomy_exists( $taxonomy ) ) {
				return new WP_Error( 'invalid_taxonomy', __( 'Invalid taxonomy.' ) );
			}
		}
	}

	// Don't pass suppress_filter to WP_Term_Query.
	$suppress_filter = $args['suppress_filter'];
	unset( $args['suppress_filter'] );

	$terms = $term_query->query( $args );

	// Count queries are not filtered, for legacy reasons.
	if ( ! is_array( $terms ) ) {
		return $terms;
	}

	if ( $suppress_filter ) {
		return $terms;
	}

	/**
	 * Filters the found terms.
	 *
	 * @since 2.3.0
	 * @since 4.6.0 Added the `$term_query` parameter.
	 *
	 * @param array         $terms      Array of found terms.
	 * @param array|null    $taxonomies An array of taxonomies if known.
	 * @param array         $args       An array of get_terms() arguments.
	 * @param WP_Term_Query $term_query The WP_Term_Query object.
	 */
	return apply_filters( 'get_terms', $terms, $term_query->query_vars['taxonomy'], $term_query->query_vars, $term_query );
}