weakhashmap
WeakHashMap类的size()方法 (WeakHashMap Class size() method)
size() method is available in java.util package.
size()方法在java.util包中可用。
size() method is used to get the number of key-value pairs that exist in this map.
size()方法用于获取此映射中存在的键值对的数量。
size() method is a non-static method, it is accessible with the class object only and if we try to access the method with the class name then we will get an error.
size()方法是一种非静态方法，只能通过类对象访问，如果尝试使用类名称访问该方法，则会收到错误消息。
size() method does not throw an exception at the time of returning the size of this map.
返回此地图的大小时， size()方法不会引发异常。
Syntax:
句法：
public int size();
Parameter(s):
参数：
It does not accept any parameter.
它不接受任何参数。
Return value:
返回值：
The return type of the method is int, it returns the cardinality (i.e. the number of key-value pair exists) of this map.
方法的返回类型为int ，它返回此映射的基数(即，存在键值对的数量)。
Example:
例：
// Java program to demonstrate the example
// of int size() method of WeakHashMap
import java.util.*;
public class SizeOfWeakHashMap {
public static void main(String[] args) {
// Instantiates a WeakHashMap object
Map < Integer, String > map = new WeakHashMap < Integer, String > ();
// By using put() method is to add
// key-value pairs in a WeakHashMap
map.put(10, "C");
map.put(20, "C++");
map.put(50, "JAVA");
map.put(40, "PHP");
map.put(30, "SFDC");
//Display WeakHashMap
System.out.println("WeakHashMap: " + map);
// By using size() method is to return
// the size of this WeakHashMap
int size = map.size();
// Display size
System.out.print("map.size(): " + size);
}
}
Output
输出量
WeakHashMap: {30=SFDC, 40=PHP, 10=C, 20=C++, 50=JAVA}
map.size(): 5
翻译自: https://www.includehelp.com/java/weakhashmap-size-method-with-example.aspx
weakhashmap
