Java AbstractSet equals()方法及实例

Java AbstractSet中的AbstractSet.equals()方法用于检查两个集合之间是否相等。它验证了作为参数传递的一个集合的元素是否等于这个集合的元素。

语法

AbstractSet1.equals(AbstractSet2)

参数： 该方法接受一个抽象集合类型的参数AbstractSet2，并且指的是要与该抽象集合进行等价检查的集合。

返回值： 如果两个对象集的平等性都成立，该方法返回真，否则返回假。

下面的程序说明了AbstractSet.equals()方法的工作。

程序1 :

// Java code to illustrate the equals() method
import java.util.*;
  
public class Abstract_Set_Demo {
    public static void main(String[] args)
    {
  
        // Creating an empty AbstractSet
        AbstractSet<String>
            abstract_set1 = new HashSet<String>();
        AbstractSet<String>
            abstract_set2 = new HashSet<String>();
  
        // Adding elements to set
        abstract_set1.add("Geeks");
        abstract_set1.add("4");
        abstract_set1.add("Geeks");
        abstract_set1.add("Welcomes");
        abstract_set1.add("You");
  
        // Adding elements to set
        abstract_set2.add("Geeks");
        abstract_set2.add("4");
        abstract_set2.add("Geeks");
        abstract_set2.add("Welcomes");
        abstract_set2.add("You");
  
        // Displaying the first HashSet
        System.out.println("First Set: "
                           + abstract_set1);
  
        // Displaying the second HashSet
        System.out.println("Second Set: "
                           + abstract_set2);
  
        // Displaying the equality
        System.out.println("Equality: "
                           + abstract_set1
                                 .equals(abstract_set2));
    }
}

输出。

First Set: [4, Geeks, You, Welcomes]
Second Set: [4, Geeks, You, Welcomes]
Equality: true

程序 2:

// Java code to illustrate the equals() method
import java.util.*;
  
public class Abstract_Set_Demo {
    public static void main(String[] args)
    {
  
        // Creating an empty AbstractSet
        AbstractSet<String>
            abstract_set1 = new HashSet<String>();
        AbstractSet<String>
            abstract_set2 = new HashSet<String>();
  
        // Adding elements to set
        abstract_set1.add("Geeks");
        abstract_set1.add("4");
        abstract_set1.add("Geeks");
        abstract_set1.add("Welcomes");
        abstract_set1.add("You");
  
        // Adding elements to set
        abstract_set2.add("Geeks");
        abstract_set2.add("4");
        abstract_set2.add("Geeks");
        abstract_set2.add("Welcomes");
        abstract_set2.add("U");
  
        // Displaying the first HashSet
        System.out.println("First Set: "
                           + abstract_set1);
  
        // Displaying the second HashSet
        System.out.println("Second Set: "
                           + abstract_set2);
  
        // Displaying the equality
        System.out.println("Equality: "
                           + abstract_set1
                                 .equals(abstract_set2));
    }
}

输出。

First Set: [4, Geeks, You, Welcomes]
Second Set: [4, U, Geeks, Welcomes]
Equality: false