Chinese descent in Vietnam is Chinese Vietnamese.
Chinese descent in Malaysia is Chinese Malaysian.
Chinese descent in US is Chinese American.
As I mentioned, in other countries Chinese blends into the culture and local national education making their mother tongue also their national language.
In Malaysia, most chinese speak in own dialect as their mother tongue and speak crappy national language, which is in reverse of chinese in other countries.
We are just weird in our own way ...
But if u as malaysian chinese that duno chinese in malaysia, the other malaysian chinese(especially older chinese folks) will look very weird on you. Hope u understand. Cheers..