In February it was hinted that WhatsApp will soon let you decide who can add you to the groups. Facebook-owned company WhatsApp has now rolled out this feature. The App now lets you stop people from adding you to groups you never wanted to join. They can not add you in any group if they’re not a contact in your address book.
As a user, you can stop anyone at all from being able to add you to the groups.
WhatsApp says the feature will be found under Settings > Account > Privacy > Groups and will begin rolling out today. It should be available to everyone in a few weeks.