Java AbstractMap equals()方法及实例

Java中的AbstractMap.equals()方法用于检查两个地图之间是否相等。它验证作为参数传递的一个地图的元素是否与这个地图的元素相等。

语法

AbstractMap1.equals(AbstractMap2)

参数： 该方法接受一个抽象哈希图类型的参数ihashmap2，指的是要与该抽象图检查相等关系的地图。

返回值： 如果两个对象地图的平等性都成立，该方法返回真，否则返回假。

下面的程序说明了AbstractMap.equals()方法的工作。

程序1 :

// Java code to illustrate the equals() method
import java.util.*;
  
public class Abstract_Map_Demo {
    public static void main(String[] args)
    {
  
        // Creating an empty AbstractMap
        AbstractMap<Integer, String>
            abstract_hash1 = new IdentityHashMap<Integer, String>();
  
        AbstractMap<Integer, String>
            abstract_hash2 = new IdentityHashMap<Integer, String>();
  
        // Mapping string values to int keys
        abstract_hash1.put(10, "Geeks");
        abstract_hash1.put(15, "4");
        abstract_hash1.put(20, "Geeks");
        abstract_hash1.put(25, "Welcomes");
        abstract_hash1.put(30, "You");
  
        // Mapping string values to int keys
        abstract_hash2.put(10, "Geeks");
        abstract_hash2.put(15, "4");
        abstract_hash2.put(20, "Geeks");
        abstract_hash2.put(25, "Welcomes");
        abstract_hash2.put(30, "You");
  
        // Displaying the AsbstractMap
        System.out.println("First Map: "
                           + abstract_hash1);
  
        // Displaying the final AbstractMap
        System.out.println("Second Map: "
                           + abstract_hash2);
  
        // Displaying the equality
        System.out.println("Equality: "
                           + abstract_hash1.equals(abstract_hash2));
    }
}

输出。

First Map: {10=Geeks, 30=You, 20=Geeks, 25=Welcomes, 15=4}
Second Map: {10=Geeks, 30=You, 20=Geeks, 25=Welcomes, 15=4}
Equality: true

程序 2:

// Java code to illustrate the equals() method
  
import java.util.*;
  
public class Abstract_Map_Demo {
    public static void main(String[] args)
    {
  
        // Creating an empty AbstractMap
        AbstractMap<Integer, String>
            abstract_hash1 = new IdentityHashMap<Integer, String>();
  
        AbstractMap<Integer, String>
            abstract_hash2 = new IdentityHashMap<Integer, String>();
  
        // Mapping string values to int keys
        abstract_hash1.put(10, "Geeks");
        abstract_hash1.put(15, "4");
        abstract_hash1.put(20, "Geeks");
        abstract_hash1.put(25, "Welcomes");
        abstract_hash1.put(30, "You");
  
        // Mapping string values to int keys
        abstract_hash2.put(10, "Geeks");
        abstract_hash2.put(15, "4");
        abstract_hash2.put(20, "Geek");
        abstract_hash2.put(25, "Welcomes");
        abstract_hash2.put(30, "You");
  
        // Displaying the IdentityHashMap
        System.out.println("First Map: "
                           + abstract_hash1);
  
        // Displaying the final IdentityHashMap
        System.out.println("Second Map: "
                           + abstract_hash2);
  
        // Displaying the equality
        System.out.println("Equality: "
                           + abstract_hash1.equals(abstract_hash2));
    }
}

输出。

First Map: {10=Geeks, 30=You, 20=Geeks, 25=Welcomes, 15=4}
Second Map: {10=Geeks, 30=You, 20=Geek, 25=Welcomes, 15=4}
Equality: false