What is the difference between count(0), count(1).. and count(*) in mySQL/SQL?

Question

I was recently asked this question in an interview. I tried this in mySQL, and got the same results(final results). All gave the number of rows in that particular table. Can

Answer 1

1) count(any integer value) is faster than count(*) ---> gives all counts including null values

2) count(column_name) omits null

Ex-->

column name=> id

values => 1 1 null null 2 2

==> count(0), count(1), count(*) -----> result is 6 only

==> count(id) ----> result is 4