Exercise: Flow Control

Questions for: Flow Control

What will be the output of the program? 
int I = 0;
label:
    if (I < 2) {
    System.out.print("I is " + I);
    I++;
    continue label;
}
A:
I is 0
B:
I is 0 I is 1
C:
Compilation fails.
D:
None of the above
Answer: C

The code will not compile because a continue statement can only occur in a looping construct. If this syntax were legal, the combination of the continue and the if statements would create a kludgey kind of loop, but the compiler will force you to write cleaner code than this.

📖
📝
💬
👁️
What will be the output of the program? 
int i = 0, j = 5; 
tp: for (;;) 
    {
        i++;  
        for (;;) 
        {
            if(i > --j) 
            {
                break tp; 
            } 
        } 
        System.out.println("i =" + i + ", j = " + j);
A:
i = 1, j = 0
B:
i = 1, j = 4
C:
i = 3, j = 4
D:
Compilation fails.
Answer: D

If you examine the code carefully you will notice a missing curly bracket at the end of the code, this would cause the code to fail.

📖
📝
💬
👁️
What will be the output of the program? 
public class Switch2 
{
    final static short x = 2;
    public static int y = 0;
    public static void main(String [] args) 
    {
        for (int z=0; z < 4; z++) 
        {
            switch (z) 
            {
                case x: System.out.print("0 ");
                default: System.out.print("def ");
                case x-1: System.out.print("1 ");  
                            break;
                case x-2: System.out.print("2 ");
            }
        }
    }
}
A:
0 def 1
B:
2 1 0 def 1
C:
2 1 0 def def
D:
2 1 0 def 1 def 1
Answer: D

When z == 0 , case x-2 is matched. When z == 1, case x-1 is matched and then the break occurs. When z == 2, case x, then default, then x-1 are all matched. When z == 3, default, then x-1 are matched. The rules for default are that it will fall through from above like any other case (for instance when z == 2), and that it will match when no other cases match (for instance when z==3).

📖
📝
💬
👁️
What will be the output of the program? 
boolean bool = true; 
if(bool = false) /* Line 2 */
{
    System.out.println("a"); 
} 
else if(bool) /* Line 6 */
{
    System.out.println("b"); 
} 
else if(!bool) /* Line 10 */
{
    System.out.println("c"); /* Line 12 */
} 
else 
{
    System.out.println("d"); 
}
A:
a
B:
b
C:
c
D:
d
Answer: C

Look closely at line 2, is this an equality check (==) or an assignment (=). The condition at line 2 evaluates to false and also assigns false to bool. bool is now false so the condition at line 6 is not true. The condition at line 10 checks to see if bool is not true ( if !(bool == true) ), it isn't so line 12 is executed.

📖
📝
💬
👁️
What will be the output of the program? 
public class Test 
{  
    public static void main(String args[]) 
    { 
        int i = 1, j = 0; 
        switch(i) 
        { 
            case 2: j += 6; 
            case 4: j += 1; 
            default: j += 2; 
            case 0: j += 4; 
        } 
        System.out.println("j = " + j); 
    } 
}
A:
j = 0
B:
j = 2
C:
j = 4
D:
j = 6
Answer: D

Because there are no break statements, the program gets to the default case and adds 2 to j, then goes to case 0 and adds 4 to the new j. The result is j = 6.

📖
📝
💬
👁️
Ad Slot (Above Pagination)
Quiz