Modifying local variable from inside lambda

Question

Modifying a local variable in forEach gives a compile error:

Normal

    int ordinal = 0;
    for (Example s : list) {
          


        

Answer 1

If you only need to pass the value from the outside into the lambda, and not get it out, you can do it with a regular anonymous class instead of a lambda:

list.forEach(new Consumer() {
    int ordinal = 0;
    public void accept(Example s) {
        s.setOrdinal(ordinal);
        ordinal++;
    }
});