Java OCA OCP Practice Question 331

Question

What is the output of the following program? 

1: public class Main { 
2:  public static void main(String[] args) { 
3:    boolean myBoolean = true; 
4:    int count = 0; 
5:    int x = 3; 
6:    while(count++ < 3) { 
7:      int y = (1 + 2 * count) % 3; 
8:      switch(y) { 
9:         default: 
10:         case 0: x -= 1; break; 
11:         case 1: x += 5; 
12:      } /*w w w. ja  va 2s .c om*/
13:    } 
14:    System.out.println(x); 
15: } 
16:}
  • A. 4
  • B. 5
  • C. 6
  • D. 7
  • E. 13
  • F. The code will not compile because of line 7. 


C.

Note

The code compiles and runs without issue; therefore, option F is incorrect.

This type of problem is best examined one loop iteration at a time:

The loop continues as count loop expression evaluates to 0 < 3, which is true, with y taking a new value of 1.

The value of y is set to: 

y = (1 + 2 * 1) % 3 
  = (1 + 2) % 3 
  = 3 % 3 
  = 0

The first case block is called and the value of x is then set to: 

x = 3 - 1 = 2

The loop continues as count loop expression evaluates to 1 < 3, which is true, with y taking a new value of 2.

The value of y is set to: 

y = (1 + 2 * 2) % 3 
  = (1 + 4) % 3 
  = 4 % 3  
  = 2

The default block is called and the value of x is set to: 

x = 2 - 1 = 1

The loop continues as the count loop expression evaluates to 2 < 3, which is true, with y taking a new value of 3.

The value of y is set to: 

y = (1 + 2 * 3) % 3 
  = (1 + 6) % 3 
  = 7 % 3  
  = 1

The second case block is called and the value of x is then set to: 

x = 1 + 5 = 6

The loop ends as the count loop expression evaluates to 3 < 3, with y also taking a new value of 4.

The most recent value of x, 6, is output, so the answer is option C.




PreviousNext

Related