I have the next code snippet, where the sonarlint tool says that my boolean variable sentinel always evaluates to true, and the sentinel = true it's an useless asingment.
import static java.lang.System.*;
public class Sentinel {
private static final int[] array = new int[] { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
public static void main(String[] args) {
boolean sentinel = false;
int counter = 0;
while (!sentinel) {
out.println( "Counter: " + counter);
out.println( "Array index: " + array[counter] );
counter++;
if ( counter == array.length - 1 ) {
out.println( "End of the array reached" );
sentinel = true;
out.println( "Breaking..." );
break;
}
}
}
}
What could be the issue with the sonarlint analisys? Code compiles perfectly and runs as intended.
Regards.
Update:
@kkk have provided two valuable answers. See below, but I let here the one that i liked more:
import java.util.concurrent.atomic.AtomicBoolean;
import static java.lang.System.*;
public class Sentinel {
private static final int[] array = new int[] { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
public static void main(String[] args) {
AtomicBoolean sentinel = new AtomicBoolean(false);
int counter = 0;
while ( !sentinel.get() ) {
out.println( "Counter: " + counter);
out.println( "Array index: " + array[counter] );
counter++;
if ( counter == array.length - 1 ) {
out.println( "Counter limit reached" );
sentinel.set( true );
out.println( "Breaking..." );
break;
}
}
}
}
make sentinel static or user AtomicBoolean,it's visibility problem
The change made by sentinel = true; is never seen by while (!sentinel). That's because of the break statement.
With that said, your code is much simpler with a for loop. Your while simply makes it complex.
for(int counter = 0; counter < array.length; counter++) {
out.println("Counter: " + counter);
out.println("Array index: " + array[counter]);
if (counter == array.length - 1) {
out.println("End of the array reached");
out.println("Breaking...");
}
}
Or, even better, do the counter == array.length - 1 actions after the loop
for(int counter = 0; counter < array.length; counter++) {
out.println("Counter: " + counter);
out.println("Array index: " + array[counter]);
}
out.println("End of the array reached");
out.println("Breaking...");