what's the continue functionality in do/while loop?

[leon ting]

in scjp 310-035 QUESTION 63.
Given:
1. public class Alpha1 {
2. public static void main( String[] args ) {
3. boolean flag; int i=0;
5. do {
6. flag = false;
7. System.out.println( i++ );
8. flag = i < 10;
9. continue;
10. } while ( (flag)? true:false );
11. }
12. }

i only for sure the use of 'continue' in for loop, but in do/while, it seems has no effect. any guide appreciate!

[Joyce Lee]

Hi Leon,

You won't see the effect by placing the continue at the end of the do/while loop. Try adding some conditions like this:

boolean flag; int i=0;
do {
    flag = false;
    System.out.println( i++ );
    flag = i < 10;
            
    if (i != 5)
        continue;
                
    System.out.println("int: " + i + " avoided continue!");
} while ( (flag)? true:false );

Joyce

[Garrett Rowe]

while ( (flag)? true:false );

Now thats what I call redundant.

[Joyce Lee]

Hi Garrett,

while ( (flag)? true:false );
Now thats what I call redundant.

You'll tend to see this kind of funny code in mock questions. The purpose is to test our understanding of Java syntax, not on good programming practice.

Joyce

[Shanel Jacob]

Hi all, what does the "while ( (flag)? true:false );" mean? I'm looking at K&B 1.4, under the control section but can't seem to find an example that explains the "?" question mark, the ":" seem like an assertion to me. What is the "while" trying to compare?

[wise owen]

Conditional Operator

[Shanel Jacob]

I tried setting "false" to "true" and the loop ran 10 times. This I can understand. But why is it that the loop can still go through 10 times with "flag" set to "false":

while ( (flag)? true:false );

"flag" was set to false initially and the conditional operator still assign "false" to "flag".

[wise owen]

flag = false;
System.out.println( i++ );
flag = i < 10; //You reset flag value base on i.

[Shanel Jacob]

Thank you Wise!