get_metadata()

get_metadata() — Retrieves the value of a metadata field for the specified object type and ID. If the meta field exists, a single value is returned if $single is true, or an array of values if it’s false. If the meta field does not exist, the result depends on get_metadata_default(). By default, an empty string is returned if $single is true, or an empty array if it’s false.

Inputs: $meta_type (string): Type of object metadata is for. Accepts ‘blog’, ‘post’, ‘comment’, ‘term’, ‘user’, or any other object type with an associated meta table. $object_id (int): ID of the object metadata is for. $meta_key (string): Optional. Metadata key. If not specified, retrieve all metadata for the specified object. Default empty string. $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 false.

Returns mixed: An array of values if $single is false. The value of the meta field if $single is true. False for an invalid $object_id (non-numeric, zero, or negative value), or if $meta_type is not specified. An empty array if a valid but non-existing object ID is passed and $single is false. An empty string if a valid but non-existing object ID is passed and $single is true. The same empty array or empty string if $meta_type has no metadata table, in which case there is no cache to return even when $meta_key is not specified. Note: Non-serialized values are returned as strings: false values are returned as empty strings (”) true values are returned as ‘1’ numbers (both integer and float) are returned as strings Arrays and objects retain their original type. These conversions apply to stored values. A default value registered with register_meta() is never stored, so it is returned with the type it was registered with, which may be an integer, float, or boolean.