Another use for break
As well as being of central importance in switch-statements,
break can also be useful inside for-loops and while-loops.
It's a way to exit the loop early.
for (var i=0; i < aliens.length; i++) {
aliens[i].do_something();
if (game_over) break;
}
In the example above, the for-loop will do something for each alien in the alien array, but if a boolean variable called game_over becomes true, the for-loop will exit and the remainder of the aliens will not be processed.