how to use if condition using count in sql code example

Example 1: sql count condition

SELECT count(CASE WHEN gender = 'F' THEN 1 ELSE NULL END) women_count,
       count(CASE WHEN gender = 'M' THEN 1 ELSE NULL END) men_count
FROM people;

Example 2: sql count if

COUNT(CASE WHEN <condition> THEN 1 END)