What is the output of the following snippet? #include <iostream> #include <string> using namespace std; int f(int a) { return a + a; } int main() { int i = 0; for(int a = 0; a < 2; a++) i = f(i + 1); cout << i; return 0; } 9 6 3 2

The output of the given C++ code snippet is 6.

Here's the step-by-step explanation:

1. The function f(int a) is defined to return the double of the input a.

2. In the main() function, an integer i is initialized with the value 0.

3. A for loop is set up to run twice (a < 2), with a starting from 0.

4. In each iteration of the loop, i is updated to be the result of f(i + 1).

5. In the first iteration, i is 0, so i + 1 is 1. The function f(1) returns 1 + 1 = 2, so i is updated to 2.

6. In the second iteration, i is 2, so i + 1 is 3. The function f(3) returns 3 + 3 = 6, so i is updated to 6.

7. After the loop, the value of i (which is 6) is printed to the console.

So, the correct answer is 6.