Lists, Logic, and Loops - Java 6 - page 104

The continue keyword starts the loop over at the next iteration. For do and while loops,
this means that the execution of the block statement starts over again; with for loops, the
increment expression is evaluated, and then the block statement is executed.
The continue keyword is useful when you want to make a special case out of elements
within a loop. With the previous example of copying one array to another, you could test
for whether the current element is equal to 1 and use continue to restart the loop after
every 1 so that the resulting array never contains zero. Note that because you're skipping
elements in the first array, you now have to keep track of two different array counters:
int count = 0;
int count2 = 0;
while (count++ <= array1.length) {
if (array1[count] == 1)
continue;
array2[count2++] = (float)array1[count];
}>
Labeled Loops
Both break and continue can have an optional label that tells Java where to resume exe-
cution of the program. Without a label, break jumps outside the nearest loop to an
enclosing loop or to the next statement outside the loop. The continue keyword restarts
the loop it is enclosed within. Using break and continue with a label enables you to use
break to go to a point outside a nested loop or to use continue to go to a loop outside
the current loop.
To use a labeled loop, add the label before the initial part of the loop, with a colon
between the label and the loop. Then, when you use break or continue , add the name of
the label after the keyword itself, as in the following:
out:
for (int i = 0; i <10; i++) {
while (x < 50) {
if (i * x++ > 400)
break out;
// inner loop here
}
// outer loop here
}
In this snippet of code, the label out labels the outer loop. Then, inside both the for and
while loops, when a particular condition is met, a break causes the execution to break
out of both loops. Without the label out , the break statement would exit the inner loop
and resume execution with the outer loop.