问在Java中迭代列表的方法？

// Not recommended (see below)!

for (int i = 0; i < list.size(); i++) {

    E element = list.get(i);

    // 1 - can call methods of element

    // 2 - can use i to make index-based calls to methods of list

    // ...

}

for (E element : list) {

    // 1 - can call methods of element

    // ...

}

for (Iterator<E> iter = list.iterator(); iter.hasNext(); ) {

    E element = iter.next();

    // 1 - can call methods of element

    // 2 - can use iter.remove() to remove the current element from the list

    // ...

}

for (ListIterator<E> iter = list.listIterator(); iter.hasNext(); ) {

    E element = iter.next();

    // 1 - can call methods of element

    // 2 - can use iter.remove() to remove the current element from the list

    // 3 - can use iter.add(...) to insert a new element into the list

    //     between element and iter->next()

    // 4 - can use iter.set(...) to replace the current element

    // ...

}

list.stream().map(e -> e + 1); // can apply a transformation function for e

Iterable.forEach，Stream.forEach，...

Arrays.asList(1,2,3,4).forEach(System.out::println);

// 1 - can call methods of an element

// 2 - would need reference to containing object to remove an item

//     (TODO: someone please confirm / deny this)

// 3 - functionally separates iteration from the action

//     being performed with each item.

Arrays.asList(1,2,3,4).stream().forEach(System.out::println);

// same capabilities as above plus potentially greate

// utilization of parallelism

// (caution: consequently, order of execution is not guaranteed,

// see [Stream.forEachOrdered][stream-foreach-ordered] for more

// information about this.)