WP_Query::is_tax() WP 3.1.0

Is the query for an existing custom taxonomy archive page?

If the $taxonomy parameter is specified, this function will additionally check if the query is for that specific $taxonomy.

If the $term parameter is specified in addition to the $taxonomy parameter, this function will additionally check if the query is for one of the terms specified.

This is a method of the class: WP_Query

No Hooks.

Return

true/false. True for custom taxonomy archive pages, false for built-in taxonomies (category and tag archives).

Usage

$WP_Query = new WP_Query();
$var = $WP_Query->is_tax( $taxonomy, $term );

$taxonomy(mixed)

Taxonomy slug or slugs.
Default: ''

$term(mixed)

Term ID, name, slug or array of Term IDs, names, and slugs.
Default: ''

Code of WP Query::is tax: wp-includes/class-wp-query.php ^{WP 5.2}

<?php
public function is_tax( $taxonomy = '', $term = '' ) {
	global $wp_taxonomies;

	if ( ! $this->is_tax ) {
		return false;
	}

	if ( empty( $taxonomy ) ) {
		return true;
	}

	$queried_object = $this->get_queried_object();
	$tax_array      = array_intersect( array_keys( $wp_taxonomies ), (array) $taxonomy );
	$term_array     = (array) $term;

	// Check that the taxonomy matches.
	if ( ! ( isset( $queried_object->taxonomy ) && count( $tax_array ) && in_array( $queried_object->taxonomy, $tax_array ) ) ) {
		return false;
	}

	// Only a Taxonomy provided.
	if ( empty( $term ) ) {
		return true;
	}

	return isset( $queried_object->term_id ) &&
		count(
			array_intersect(
				array( $queried_object->term_id, $queried_object->name, $queried_object->slug ),
				$term_array
			)
		);
}