if <expression>
   % statement(s) will execute if the boolean expression is true 
   <statement(s)>
else
   <statement(s)>
   % statement(s) will execute if the boolean expression is false 
end

a = 100;
% check the boolean condition 
   if a < 20 
      % if condition is true then print the following 
      fprintf('a is less than 20\n' );
   else
      % if condition is false then print the following 
      fprintf('a is not less than 20\n' );
   end
   fprintf('value of a is : %d\n', a);

a is not less than 20
value of a is : 100