get_post_custom_keys() │ WP 1.2.0

Retrieve meta field names for a post.

If there are no meta fields, then nothing (null) will be returned.

Uses: get_post_custom()

Used By: the_meta()

No Hooks.

Return

Array|null. Array of the keys, if retrieved.

Usage

get_post_custom_keys( $post_id );

$post_id(int): Post ID.
Default: ID of the global $post

Examples

#1 Get the meta-field keys of the current post

The following example will pass the variable $custom_field_keys - an array containing the keys of the custom fields of the current post and then display those keys.

$custom_field_keys = get_post_custom_keys();

foreach ( $custom_field_keys as $key => $value ) {

	$val = trim( $value );
	if ( '_' === $val[0] ) {
		continue;
	}

	echo "$key => $value<br />";
}

/* Result:

Suppose the post contains custom fields named 'mykey' and 'yourkey',
then we will see on the screen:

0 => mykey
1 => yourkey

*/

If you remove the condition if ( '_' === $val[0] ) from the loop, the internal custom post fields that WordPress uses, such as _edit_last and _edit_lock, will also be displayed. This condition is needed to exclude such custom field keys.

Changelog

Since 1.2.0

Introduced.

`get_post_custom_keys() get post custom keys` code ^{WP 6.1.1}

wp-includes/post.php

function get_post_custom_keys( $post_id = 0 ) {
	$custom = get_post_custom( $post_id );

	if ( ! is_array( $custom ) ) {
		return;
	}

	$keys = array_keys( $custom );
	if ( $keys ) {
		return $keys;
	}
}