Java 计算两个集合之间的差异

在本文中，我们将了解如何计算两个集合之间的差异。集合是一种不包含重复元素的集合。它模拟了数学集合的抽象。Set接口仅包含从Collection继承的方法，并添加了禁止重复元素的限制。

以下是同样的演示-

假设我们的输入是 -

First set: [90, 75, 60, 45]
Second set: [90, 60]

期望的输出应该是 −

After subtraction of two sets:
[75, 45]

步骤

Step 1 - START
Step 2 - Declare namely
Step 3 - Define the values.
Step 4 - Create two Sets, and add elements to it using the ‘add’ method.
Step 5 - Display the Sets on the console.
Step 6 - Compute the difference of the sets using the ‘removeAll’ method.
Step 7 - Display the difference of sets on the console.
Step 8 - Stop

示例1

在这里，我们将所有的操作都绑定在‘main’函数下面。

import java.util.HashSet;
import java.util.Set;
public class Demo {
   public static void main(String[] args) {
      System.out.println("The required packages have been imported");
      Set<Integer> input_set_1 = new HashSet<>();
      input_set_1.add(45);
      input_set_1.add(60);
      input_set_1.add(75);
      input_set_1.add(90);
      System.out.println("The first set is defined as: " + input_set_1);
      Set<Integer> input_set_2 = new HashSet<>();
      input_set_2.add(60);
      input_set_2.add(90);
      System.out.println("The second set is defined as: " + input_set_2);
      input_set_1.removeAll(input_set_2);
      System.out.println("\nAfter subtraction of two sets: \n" + input_set_1);
   }
}

输出

The required packages have been imported
The first set is defined as: [90, 75, 60, 45]
The second set is defined as: [90, 60]

After subtraction of two sets:
[75, 45]

示例2

在这里，我们将操作封装到展示面向对象编程的函数中。

import java.util.HashSet;
import java.util.Set;
public class Demo {
   static void subtract(Set<Integer> input_set_1, Set<Integer> input_set_2){
      input_set_1.removeAll(input_set_2);
      System.out.println("\nAfter subtraction of two sets: \n" + input_set_1);
   }
   public static void main(String[] args) {
      System.out.println("The required packages have been imported");
      Set<Integer> input_set_1 = new HashSet<>();
      input_set_1.add(45);
      input_set_1.add(60);
      input_set_1.add(75);
      input_set_1.add(90);
      System.out.println("The first set is defined as: " + input_set_1);
      Set<Integer> input_set_2 = new HashSet<>();
      input_set_2.add(60);
      input_set_2.add(90);
      System.out.println("The second set is defined as: " + input_set_2);
      subtract(input_set_1, input_set_2);
   }
}

输出

The required packages have been imported
The first set is defined as: [90, 75, 60, 45]
The second set is defined as: [90, 60]

After subtraction of two sets:
[75, 45]