Loops

The four forms

for when you know the count, while when you loop until a condition, do-while to run the body at least once, and the enhanced for (for-each) to walk any array or Iterable.

int[] nums = {2, 4, 6};
int sum = 0;
for (int n : nums) sum += n;      // for-each

int i = 0;
while (i < 3) { System.out.print(i); i++; }

break, continue, labels

break exits the innermost loop; continue skips to the next iteration. A labelled break outer; can jump out of nested loops — use sparingly.