get_metadata_default( string $meta_type, int $object_id, string $meta_key, bool $single = false )

Retrieves default metadata value for the specified meta key and object.

Description

By default, an empty string is returned if $single is true, or an empty array if it’s false.

Parameters

$meta_type

(string) (Required) Type of object metadata is for. Accepts 'post', 'comment', 'term', 'user', or any other object type with an associated meta table.

$object_id

(int) (Required) ID of the object metadata is for.

$meta_key

(string) (Required) Metadata key.

$single

(bool) (Optional) If true, return only the first value of the specified $meta_key. This parameter has no effect if $meta_key is not specified.

Default value: false

Return

(mixed) An array of default values if $single is false. The default value of the meta field if $single is true.

Source

File: wp-includes/meta.php

function get_metadata_default( $meta_type, $object_id, $meta_key, $single = false ) {
	if ( $single ) {
		$value = '';
	} else {
		$value = array();
	}

	/**
	 * Filters the default metadata value for a specified meta key and object.
	 *
	 * The dynamic portion of the hook, `$meta_type`, refers to the meta object type
	 * (post, comment, term, user, or any other type with an associated meta table).
	 *
	 * Possible filter names include:
	 *
	 *  - `default_post_metadata`
	 *  - `default_comment_metadata`
	 *  - `default_term_metadata`
	 *  - `default_user_metadata`
	 *
	 * @since 5.5.0
	 *
	 * @param mixed  $value     The value to return, either a single metadata value or an array
	 *                          of values depending on the value of `$single`.
	 * @param int    $object_id ID of the object metadata is for.
	 * @param string $meta_key  Metadata key.
	 * @param bool   $single    Whether to return only the first value of the specified `$meta_key`.
	 * @param string $meta_type Type of object metadata is for. Accepts 'post', 'comment', 'term', 'user',
	 *                          or any other object type with an associated meta table.
	 */
	$value = apply_filters( "default_{$meta_type}_metadata", $value, $object_id, $meta_key, $single, $meta_type );

	if ( ! $single && ! wp_is_numeric_array( $value ) ) {
		$value = array( $value );
	}

	return $value;
}

Changelog

Version Description
5.5.0 Introduced.

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Licensed under the GNU GPLv2+ License.
https://developer.wordpress.org/reference/functions/get_metadata_default