Codeigniter : calling a method of one controller from other

Question

I have two controllers a and b.

I would like to call a method of controller a from a method of controller b.

Answer 1

test.php Controller File :

Class Test {
 function demo() {
  echo "Hello";
 }
}

test1.php Controller File :

Class Test1 {
 function demo2() {
  require('test.php');
  $test = new Test();
  $test->demo();
 }
}