Question

For each call to the following method, indicate what console output is produced:
public void mystery2(int n) {
    if (n > 100) {
        System.out.print(n);
    } else {
        mystery2(2 * n);
        System.out.print(", " + n);
    }
}

Sound F/X

mystery2(113);
mystery2(70);
mystery2(42);
mystery2(30);
mystery2(10);

Answer 1

whenever the value of n is smaller than 100 in that case the function again calls itself by doubling the value of n , as the value of n crosses 100 the n value gets printed and no more mystery2 is called . Due to backtracking the value of n which were called from else condition gets printed

public void mystery2(int n) {
    if (n > 100) {
        System.out.print(n);
    } else {
        mystery2(2 * n);
        System.out.print(", " + n);
    }
}

mystery2(113);  

Output produced: 113

mystery2(70);

Output produced: 140, 70

mystery2(42);  

Output produced: 168, 84, 42

mystery2(30);  

Output produced: 168, 84, 42

mystery2(10);

Output produced: 160, 80, 40, 20, 10