Is there any advantage of multiple insertion operators after cout over single insertion operators after cout.

Answer 1

Code readability. Also, there is a bit less to type.

I personally prefer this:
int a = 42;
cout << "The answer is " << a << "!" << endl;

...over this:
int a = 42;
cout << "The answer is "
cout << a
cout << "!"
cout << endl;

Answer 2

Because I want to print the value of the variable a instead of the character a, obviously.

Answer 3

Why dont you prefer this ?
cout << "This answer is a !" << endl;
I am asking