In this case, we’re removing an item from the list while iterating over it, which is not allowed. The solution is to use anIteratorto safely remove items from the list while iterating. 2. StackOverflowError AStackOverflowErrortypically occurs when your recursion depth is too high or you hav...
}// 16. 使用增强的for循环遍历列表System.out.println("使用增强的for循环遍历列表:");for(String item : list) { System.out.println(item); }// 17. 使用listIterator()遍历列表System.out.println("使用listIterator()遍历列表:"); ListIterator<String> listIterator = list.listIterator();while(listI...
因为linkedlist里面的元素是有序的,所以他的迭代器里面是有添加方法的,而集(set)里面的元素完全无序,所以他的迭代器接口就没有add方法。ListIterator里面的add方法就可以把元素添加到迭代器位置之前。。 如果有多个迭代器在一个集合上迭代,集合被一个迭代器或者自身修改,那么迭代器都没有意义了,就会发出异常! 列表...
因为对 list.remove(i) 的调用选择的是重载方法 remove(int i),而不是 remove(Object o)。正确的写法应该是:java for (int i = 0; i < 3; i++) { set.remove(i); list.remove((Integer) i); // or remove(Integer.valueOf(i)) }
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 ...
2.3.remove() Finally, if we want toremove the current element from the collection,we can use theremove: iter.remove(); This is a safe way to remove elements while iterating over a collection without a risk of aConcurrentModificationException. ...
2.1. Single Random Item In order to select a random index, you can use Random.nextInt(int bound) method: public void givenList_shouldReturnARandomElement() { List<Integer> givenList = Arrays.asList(1, 2, 3); Random rand = new Random(); int randomElement = givenList.get(rand.nextInt...
removeMyEventListener(MyEventListener listener) { listenerList.remove(MyEventListener.class, listener); } // This private class is used to fire MyEvents void fireMyEvent(MyEvent evt) { Object[] listeners = listenerList.getListenerList(); // Each listener occupies two elements - the first is...
import java.util.List; void main() { List<String> items = new ArrayList<>(); items.add("coins"); items.add("pens"); items.add("keys"); items.add("sheets"); items.stream().filter(item -> item.length() == 4).forEach(System.out::println); ...
Apart from methods defined inCollectioninterface, it does have its own methods also which are to manipulate the List based on the index location of the item. These methods can be grouped assearch, get, iteration and range view. All above operations support index locations. ...