Java 从ArrayList中删除重复元素

在本文中，我们将了解如何从arrayList中删除重复元素。ArrayList类是一个可调整大小的数组，可以在java.util包中找到。Java中内置数组和ArrayList之间的区别在于数组的大小不能修改。

以下是相同事物的演示 −

假设我们的输入是 −

Input list : [150, 250, 300, 250, 500, 150, 600, 750, 300]

所期望的输出应该是 −

The list with no duplicates is:
[150, 250, 300, 500, 600, 750]

步骤

Step 1 - START
Step 2 - Declare namely
Step 3 - Define the values.
Step 4 – Create an ArrayList of integer values and initialize elements in it.
Step 5 - Display the ArrayList on the console.
Step 6 - Create another linkedhashset of integers.
Step 7 - Use the ‘addAll’ method to include elements from previous ArrayList into it as elements.
Step 8 - Since it is a set, it only adds the unique values.
Step 9 - Clear the elements of the ArrayList.
Step 10- Display the set on the console with unique elements.
Step 11- Stop

示例1

在这里，我们将所有操作绑定在“main”函数下面。

import java.util.ArrayList;
import java.util.Arrays;
import java.util.LinkedHashSet;
import java.util.Set;
public class Demo {
   public static void main(String[] args) {
      System.out.println("The required packages have been imported");
      ArrayList<Integer> input_list = new ArrayList<>(Arrays.asList(150, 250, 300, 250, 500, 150, 600, 750, 300));
      System.out.println("The list is defined as: " + input_list);
      Set<Integer> temp_set = new LinkedHashSet<>();
      temp_set.addAll(input_list);
      input_list.clear();
      input_list.addAll(temp_set);
      System.out.println("\nThe list with no duplicates is: \n" + input_list);
   }
}

输出

The required packages have been imported
The list is defined as: [150, 250, 300, 250, 500, 150, 600, 750, 300]

The list with no duplicates is:
[150, 250, 300, 500, 600, 750]

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.ArrayList;
import java.util.Arrays;
import java.util.LinkedHashSet;
import java.util.Set;
public class Demo {
   static void remove_duplicates(ArrayList<Integer> input_list){
      Set<Integer> temp_set = new LinkedHashSet<>();
      temp_set.addAll(input_list);
      input_list.clear();
      input_list.addAll(temp_set);
      System.out.println("\nThe list with no duplicates is: \n" + input_list);
   }
   public static void main(String[] args) {
      System.out.println("The required packages have been imported");
      ArrayList<Integer> input_list = new ArrayList<>(Arrays.asList(150, 250, 300, 250, 500, 150, 600, 750, 300));
      System.out.println("The list is defined as: " + input_list);
      remove_duplicates(input_list);
   }
}

输出

The required packages have been imported
The list is defined as: [150, 250, 300, 250, 500, 150, 600, 750, 300]

The list with no duplicates is:
[150, 250, 300, 500, 600, 750]