IdentityHashMap类的size()方法 (IdentityHashMap 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 return the size (i.e. How many key-value pair exists) of this IdentityHashMap.

  size()方法用于返回此IdentityHashMap的大小(即，存在多少个键值对)。

• 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 size.

  返回size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 size of this IdentityHashMap.

方法的返回类型为int ，它返回此IdentityHashMap的大小。

Example:

例：

// Java program to demonstrate the example 
// of int size() method of IdentityHashMap 
import java.util.*;
public class SizeOfIdentityHashMap {
public static void main(String[] args) {
// Instantiates a IdentityHashMap object
Map < Integer, String > map = new IdentityHashMap < Integer, String > ();
// By using put() method is to add
// key-value pairs in a IdentityHashMap
map.put(10, "C");
map.put(20, "C++");
map.put(50, "JAVA");
map.put(40, "PHP");
map.put(30, "SFDC");
//Display IdentityHashMap
System.out.println("IdentityHashMap: " + map);
// By using size() method is to return
// the size of this IdentityHashMap
int size = map.size();
// Display size
System.out.print("map.size(): " + size);
}
}

Output

输出量

IdentityHashMap: {20=C++, 40=PHP, 50=JAVA, 30=SFDC, 10=C}
map.size(): 5

翻译自: https://www.includehelp.com/java/identityhashmap-size-method-with-example.aspx