Example Code Ch 12-2
Given the following recursive factorial method:
public int factorial(int x)
{
if (x 1) return x * factorial (x - 1);
else return 1;
}
-Refer to Example Code Ch 12-2: What is returned if factorial(3) is called?
A) 0
B) 1
C) 3
D) 6
E) 9

Question

Example Code Ch 12-2
Given the following recursive factorial method:
public int factorial(int x)
{
if (x > 1) return x * factorial (x - 1);
else return 1;
}
-Refer to Example Code Ch 12-2: What is returned if factorial(3) is called?
A) 0
B) 1
C) 3
D) 6
E) 9

Quizplus · Accepted Answer

When factorial(3) is called, the method checks if x is greater than 1, which is true, so it returns 3 * factorial(2). In turn, factorial(2) checks if its x value is greater than 1, which is also true, so it returns 2 * factorial(1). Finally, factorial(1) checks if its x value is greater than 1, which is false, so it returns 1. Backtracking to factorial(2), it multiplies 2 by the returned value of factorial(1) which is 1, resulting in 2. Backtracking again to factorial(3), it multiplies 3 by the returned value of factorial(2) which is 2, resulting in 6. Thus, the correct answer is D) 6.