Break

    The break statement will move control outside a loop or switch statement. Stylistically speaking, break has the potential to be a bit vulgar. It’s preferable to use a straight while with a single test at the top if possible. Sometimes you are forced to use a break because the test can occur only somewhere in the midst of the statements in the loop body. To keep the code readable, be sure to make the break obvious -- forgetting to account for the action of a break is a traditional source of bugs in loop behavior.

    while (<expression>) {
       <statement>
       <statement>

       if (<condition which can only be evaluated here>)
          break;

       <statement>
       <statement>
    }
    // control jumps down here on the break

    The break does not work with if. It only works in loops and switches. Thinking that a break refers to an if when it really refers to the enclosing while has created some high quality bugs. When using a break, it’s nice to write the enclosing loop to iterate in the most straightforward, obvious, normal way, and then use the break to explicitly catch the exceptional, weird cases.

Continue

    The continue statement causes control to jump to the bottom of the loop, effectively skipping over any code below the continue. As with break, this has a reputation as being vulgar, so use it sparingly. You can almost always get the effect more clearly using an if inside your loop.

    while (<expression>) {
       …
       if (<condition>)
          continue;
       …
       …
       // control jumps here on the continue
    }