Question

What value is returned as a result of the call mystery(6) ?

public static int mystery(int n)
{
int x = 1;
int y = 1;
while (n > 2)
{
x = x + y;
y = x - y;
n--;
}
return x;
}

Answer 1

The value returned as a result of the call mystery(6) is 8. The function calculates the next number in a sequence that resembles the Fibonacci sequence, where each number is the sum of the two preceding numbers.

Step-by-step explanation:

The student has asked what value is returned as a result of the call mystery(6). This function appears to generate a sequence where each term is the sum of the previous two terms, which resembles the Fibonacci sequence. Let's walk through the function:

• Initial values: x = 1, y = 1.
• For n = 6, the while loop will execute because n is greater than 2.
• Each iteration will decrease n by 1 and reassign x and y as follows:

1. Iteration 1: x = 1 + 1 = 2, y = 2 - 1 = 1, n = 5.
2. Iteration 2: x = 2 + 1 = 3, y = 3 - 1 = 2, n = 4.
3. Iteration 3: x = 3 + 2 = 5, y = 5 - 2 = 3, n = 3.
4. Iteration 4: x = 5 + 3 = 8, y = 8 - 3 = 5, n = 2.

Once n is no longer greater than 2, the loop exits, and the function returns the value of x, which is 8 in this case.