如果已知是ArrayList，从性能角度考虑，两种方法差不多。但是从软工角度考虑，推荐使用iterator。因为你的...
ArrayList<String>list=newArrayList<>();list.add("Apple");list.add("Banana");list.add("Orange");Iterator<String>iterator=list.iterator();while(iterator.hasNext()){System.out.println(iterator.next());} 1. 2. 3. 4. 5. 6. 7. 8. 9. 3. 使用增强for循环 增强for循环是Java5引入的一种...
importjava.util.ArrayList;importjava.util.Iterator;publicclassMain{publicstaticvoidmain(String[]args){ArrayList<String>list=newArrayList<>();list.add("apple");list.add("banana");list.add("orange");// 使用迭代器遍历ArrayList并删除指定元素Iterator<String>iterator=list.iterator();while(iterator.hasNex...
// 当it.hasNext()已经判断为false时,如果还想取元素,则会报异常 // java.util.NoSuchElementException // System.out.println(it.next()); //迭代器以for循环的形式使用 for(Iterator<String> it = coll.iterator(); it.hasNext();) { System.out.println(it.next()); } } 在Collection接口描述了一...
Use either a for loop with an integer index to get all the elements from an ArrayList, or go over all elements in a ArrayList using an Iterator (forward) or ListIterator (forward / backward). foreach loop. This is fast and works for all kinds of lists, but is not entirely flexible ...
示例1:Java ArrayList iterator() import java.util.ArrayList; import java.util.Iterator; class Main { public static void main(String[] args){ ArrayList<String> languages = new ArrayList<>(); // Add elements in the array list languages.add("Java"); languages.add("Python"); languages.add("...
import java.util.Iterator; import java.util.LinkedList; import java.util.List; import java.util.function.Function; import java.util.stream.Collectors; public class RemovingRows { private static final int SIZE = 600_000; public static void main(String[] args) { test("forward indexed loop", ma...
at java.util.ArrayList$Itr.next(ArrayList.java:851) at com.howtodoinjava.example.ArrayListExample.main(ArrayListExample.java:22) 5. Differences betweenIteratorandListIterator That’s all for theArrayList listIterator()in Java. Happy Learning !!
Using iterator Using enhanced for-each loop. Using list iterator Using for loop Using forEachRemaining() method. ArrayList Size We can usesize()method of ArrayList to find thenumber of elements in an ArrayList. importjava.util.ArrayList;publicclassJavaExample{publicstaticvoidmain(String[]args){Arr...
ArrayList使用Java数组来存储其元素,并根据需要自动增加或减少其大小。 当ArrayList达到其当前容量时,它会创建一个新数组,其大小是当前数组的两倍,然后将所有元素复制到新数组中。这种机制允许ArrayList高效地处理元素的添加和删除,而无需指定其初始容量。 优化: 为了优化ArrayList的性能,可以指定其初始容量。这有助于...