Java ConcurrentHashMap size()方法

来源：这里教程网时间：2026-02-17 20:42:36 作者：

Java ConcurrentHashMap size()方法

java.util.concurrent.ConcurrentHashMap.size() 方法是Java中的一个内置函数，它计算该地图中键值映射的数量并返回整数值。

语法

public int size()

返回值： 该函数返回一个整数值，表示该地图中键值映射的数量。

下面的程序说明了 size() 方法的使用。

程序 1:

// Java Program Demonstrate size()// method of ConcurrentHashMap  import java.util.concurrent.*;  class GFG {    public static void main(String[] args)    {          ConcurrentHashMap<Integer, String>            chm = new ConcurrentHashMap<Integer, String>();          chm.put(100, "Geeks");        chm.put(101, "for");        chm.put(102, "Geeks");          // Display the number of        // key-value mappings        System.out.println("The number of "                           + "key-value mappings is "                           + chm.size());    }}

输出:

The number of key-value mappings is 3

计划2。

// Java Program Demonstrate size()// method of ConcurrentHashMap  import java.util.concurrent.*;  class GFG {    public static void main(String[] args)    {          ConcurrentHashMap<Integer, Integer>            chm = new ConcurrentHashMap<Integer, Integer>();          chm.put(1, 100);        chm.put(2, 200);        chm.put(3, 300);        chm.put(4, 400);        chm.put(5, 500);        chm.put(6, 600);          // Display the number of        // key-value mappings        System.out.println("The number of "                           + "key-value mappings is "                           + chm.size());    }}

输出: