Doubtful answer

[bettina akinsuyi]

Dear comrades, i want someone to solve this. Please, good proof or explanation no room to question the message poster.



Given:

1. class Ifs {
2. public static void main(String [] args) {
3. boolean state = false;
4. int i = 1;
5. if((++i > 1) && (state = true))
6. i++;
7. if((++i > 3) || (state = false))
8. i++;
9. System.out.println(i);
10. }
11. }


What is the result?





A
3
B
4
C
5
D
Compilation fails.
E
An exception is thrown at runtime.

I think answer should be 4 because there is preincrement greater in line 7 and not 5 as the answer show in the book.

[Keith Lynn]

Originally posted by bettina akinsuyi:
Dear comrades, i want someone to solve this. Please, good proof or explanation no room to question the message poster.



Given:

1. class Ifs {
2. public static void main(String [] args) {
3. boolean state = false;
4. int i = 1;
5. if((++i > 1) && (state = true))
6. i++;
7. if((++i > 3) || (state = false))
8. i++;
9. System.out.println(i);
10. }
11. }


What is the result?





A
3
B
4
C
5
D
Compilation fails.
E
An exception is thrown at runtime.

I think answer should be 4 because there is preincrement greater in line 7 and not 5 as the answer show in the book.

Notice that in line 5, the second condition in the && is an assignment statement.

The boolean is set to true, and the value of the assignment statement is true.

So ++i in the body of the loop is executed.

[pete stein]

1. Carefully re look at your code. (state = true), not ==.
2. Run the code yourself, in a debugger if possible and walk through.

public class Ifs
{
 
    public static void myMain(String[] args)
    {
        boolean state = false;
        int i = 1;
        if ((++i > 1) && (state [B]=[/B] true))
        {
            i++;
        }
        if ((++i > 3) || (state [B]=[/B] false))
        {
            i++;
            System.out.println(i);
        }
        
    }
}

Let me know if this doesn't make sense. Good luck!
/Pete
[ March 22, 2007: Message edited by: pete stein ]