No, the blocked person won’t get any notification not of any kind. As you asked will the other person knows if you block him on WhatsApp, the straight answer would be no. But if He observes few things, then he will come to know that you had blocked him.

What Happens when you block him on whatsapp :
-> Your profile Pic, wont be visible to that person anymore, neither your online status.
-> Cant see your whatsapp status, if he sends a message, only single tick mark will appear, instead of 2 ticks.

So if He observes all these above things, He will come know that you had blocked him. Let us discuss that more clearly.

Blocking is a feature which is used to break the complete connection/ profile/ information sharing between user and the blocked person. Let’s analyze WhatsApp and Facebook and what happens after blocking.

WhatsApp:

When you block a person the first difference you’ll notice is that their DP is not visible. It will switch back to a default one. Also you won’t be able to see any information in their profile. You can’t see their story not even their status. The major thing is that they can’t send you messages. Also when you and that blocked person is added in the common group along with other members then also you can’t see the message of that person neither he/she will be able to see. These are the major changes.

Facebook:

Almost same thing also happens on Facebook. You can’t see their profile. The likes/comments won’t be shown. You can’t tag/mention them. You won’t be able to see them in your friends list. It’ll be like their profile never existed for you. Also you can’t text them neither they can message you. Same thing also will happen with FB Messenger. They won’t be able to contact you no matter what. Their DP will be set to default blank.

These things happens with all major social media platforms. Thanks! I hope your doubt is cleared.