Add meta data field to a comment.

Signature

add_comment_meta( $comment_id, $meta_key, $meta_value, $unique = false )
comment_id
 (int) Comment ID.
meta_key
 (string) Metadata name.
meta_value
 (mixed) Metadata value.
unique
 (boolean) Optional, default is false. Whether the same key should not be added.
Default: false

Return

(int|boolean) Meta ID on success, false on failure.

Source

function add_comment_meta($comment_id, $meta_key, $meta_value, $unique = false) {
	return add_metadata('comment', $comment_id, $meta_key, $meta_value, $unique);
}
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