delegate & multicast delegate

Delegate is like function pointer.

• Delegate used to invokes a function.
• Multicast delegate used to invoke more than one function.

class demo
    {
        // delegates are used to invoke function
        delegate int mathdelegate(int a, int b);
        
        public demo()
        {
            mathdelegate objDelegate = new mathdelegate(this.add);
            int result = objDelegate(10, 20);
            Console.WriteLine(result);


            //multicast delegates are used to invoke more than one function
            objDelegate += new mathdelegate(sub);
            result = objDelegate(30, 10);
            Console.WriteLine(result);

            objDelegate += new mathdelegate(mul);
            result = objDelegate(30, 10);
            Console.WriteLine(result);

            
        }

        public int add(int a, int b)
        {
            return a + b;
        }

        public int sub(int a, int b)
        {
            return a - b;
        }

        public int mul(int a, int b)
        {
            return a * b;
        }
    }