if else in plsql

declare 
a integer := 30; 
b integer := 40; 
begin 
if (a>10) then 
dbms_output.put_line(' a is greater than b'); 
else 
dbms_output.put_line('a is greater than 10'); 
end if; 
dbms_output.put_line('value of a : ' || a); 
end;