WordPress at a glance
function is not described

_get_random_header_data() WP 3.4.0

Gets random header image data from registered images in theme.

This is an internal function for using it by WP core itself. It's not recommended to use this function in your code.

No Hooks.

Return

Object.

Usage

_get_random_header_data();

Notes

  • Global. Array. $_wp_default_headers

Changelog

Since 3.4.0 Introduced.

Code of _get_random_header_data() WP 5.7.2

<?php
function _get_random_header_data() {
	static $_wp_random_header = null;

	if ( empty( $_wp_random_header ) ) {
		global $_wp_default_headers;
		$header_image_mod = get_theme_mod( 'header_image', '' );
		$headers          = array();

		if ( 'random-uploaded-image' === $header_image_mod ) {
			$headers = get_uploaded_header_images();
		} elseif ( ! empty( $_wp_default_headers ) ) {
			if ( 'random-default-image' === $header_image_mod ) {
				$headers = $_wp_default_headers;
			} else {
				if ( current_theme_supports( 'custom-header', 'random-default' ) ) {
					$headers = $_wp_default_headers;
				}
			}
		}

		if ( empty( $headers ) ) {
			return new stdClass;
		}

		$_wp_random_header = (object) $headers[ array_rand( $headers ) ];

		$_wp_random_header->url           = sprintf( $_wp_random_header->url, get_template_directory_uri(), get_stylesheet_directory_uri() );
		$_wp_random_header->thumbnail_url = sprintf( $_wp_random_header->thumbnail_url, get_template_directory_uri(), get_stylesheet_directory_uri() );
	}

	return $_wp_random_header;
}