Java中的 CopyOnWriteArraySet size() 方法

CopyOnWriteArraySet的size()方法返回 Set 的大小。它返回当前 Set 中的元素数。

句法：

public int size()

返回值：函数返回当前Set中的元素个数。

下面的程序说明了上述函数：

方案一：

// Java Program to illustrate the CopyOnWriteArraySet
// size() method in Java
  
import java.util.concurrent.CopyOnWriteArraySet;
import java.util.*;
  
public class GFG {
    public static void main(String[] args)
    {
  
        // create object of CopyOnWriteArraySet
        CopyOnWriteArraySet ArrSet
            = new CopyOnWriteArraySet();
  
        // print CopyOnWriteArraySet
        System.out.println("CopyOnWriteArraySet: "
                           + ArrSet);
  
        // size value print
        System.out.println("size of ArrSet: "
                           + ArrSet.size());
  
        // Add elements
        ArrSet.add(32);
        ArrSet.add(67);
        ArrSet.add(98);
        ArrSet.add(100);
  
        // print CopyOnWriteArraySet
        System.out.println("CopyOnWriteArraySet: "
                           + ArrSet);
  
        // size value print
        System.out.println("size of ArrSet: "
                           + ArrSet.size());
    }
}

输出：

CopyOnWriteArraySet: []
size of ArrSet: 0
CopyOnWriteArraySet: [32, 67, 98, 100]
size of ArrSet: 4

方案二：

// Java Program to illustrate the CopyOnWriteArraySet
// size() method in Java
  
import java.util.concurrent.CopyOnWriteArraySet;
import java.util.*;
  
public class GFG {
    public static void main(String[] args)
    {
  
        // create object of CopyOnWriteArraySet
        CopyOnWriteArraySet ArrSet
            = new CopyOnWriteArraySet();
  
        // Add elements
        ArrSet.add("gopal");
        ArrSet.add("gfg");
        ArrSet.add("jgec");
        ArrSet.add("sudo");
  
        // print CopyOnWriteArraySet
        System.out.println("CopyOnWriteArraySet: "
                           + ArrSet);
  
        // size value print
        System.out.println("size of ArrSet: "
                           + ArrSet.size());
    }
}

输出：

CopyOnWriteArraySet: [gopal, gfg, jgec, sudo]
size of ArrSet: 4

参考： https: Java/util/concurrent/CopyOnWriteArraySet.html#size–