Phép so sánh là: > < >= <= <> =

Vd:

- if a>b then write(a, ' lon hon ', b);

- if h1>h2 then write(ten1, ' cao hon ', ten2) else

     if h1<h2 then write(ten2, ' cao hon ', ten1) else

           write(ten1, ' bang ', ten2);

- if (m>5) and (m<10) then

     begin

           write(m, ' > 5 va ', m, ' < 10');

           write('Phep toan hoan thanh!');

      end;

- if (20 mod 3) = 0 then x:=x*3 else x:=x/5;

- if (a>b) and (a>c) and (a>d) then write(a, ' lon nhat') else write(a, ' khong lon nhat');

- if (a+b>c) or (a+c>b) or (b+c>a) then write('a, b, c la 3 canh tam giac');

- if m>0 then

      begin

            a:=5;

            m:=10;

      end

   else c:=15;