util.ArrayList; public class ArrayListDemo { public static void main(String[] args) { // create an empty array list ArrayList<Integer> arrayList = new ArrayList<>(); // use add() method to add elements in the a
线程安全的ArrayList—CopyOnWriteArrayList CopyOnWriteArrayList是基于写时复制(copy-on-write)思想来实现的一个线程安全的ArrayList集合类。它实现了List接口,内部持有一个ReentrantLock来给写上锁,底层是用volatile transient声明的数组array,它是读写分离的,写入数据时会复制出一个新的数组并加上ReentrantLock锁,完成写入后将...
System.out.println("---");//Collection<String> list2 = new ArrayList<String>();Collection<String> list2 =newArrayList<>();//JDK 7开始之后后面类型申明可以不写list2.add("Java");//list2.add(23);list2.add("黑马");// 集合和泛型不支持基本数据类型,只能支持引用数据类型//Collection<int> ...
Values() // []int{5, 1} (in insertion-order) set.Clear() // empty set.Empty() // true set.Size() // 0 } Stacks A stack that represents a last-in-first-out (LIFO) data structure. The usual push and pop operations are provided, as well as a method to peek at the top ...
Println(list) // ArrayList ["a","b"] } Sort Sort is a general purpose sort function. Lists have an in-place Sort() function and all containers can return their sorted elements via containers.GetSortedValues() function. Internally these all use the utils.Sort() method: package main ...
// java program to convert ArrayList// to LinkedHashSet// importing the utils packageimportjava.util.*;classGFG{// defining the methodvoidarrayListToLinkedHashSet(){// initializing the ArrayListArrayList<String> arrayList =newArrayList<>();// adding values in the ArrayListarrayList.add("Geeks")...
ArrayList.set(int index, E element) has the following syntax. publicE set(intindex, E element) Example In the following code shows how to use ArrayList.set(int index, E element) method. importjava.util.ArrayList;//fromwww.java2s.compublicclassMain {publicstaticvoidmain(String[] args) { ...
43 list = new ArrayList<String>(); 44 list.add("List集合"); 45 list.add("Value"); 46 47 } 48 49 @Override 50 public void onClick(View v) { 51 // TODO Auto-generated method stub 52 Intent intent = new Intent(MainActivity.this, IntentData.class); ...
public class ArrayListDemo { public static void main(String[] args) { // TODO Auto-generated method stub ArrayList<String> alist=new ArrayList<String>(); alist.add("qq"); alist.add("abc"); alist.add("aaa"); alist.add("abc"); ...
ArrayList在遍历的时候时不能修改的,即遍历的时候不能增加或者删除元素,否则会抛ConcurrentModificationException ArrayList是线程不安全的。 ArrayList源码中的主要字段 // 默认数组的大小privatestaticfinalintDEFAULT_CAPACITY=10;// 默认空数组privatestaticfinalObject[] EMPTY_ELEMENTDATA = {};// 实际存放数据的数组pri...