Java AbstractCollection removeAll()用法及代码示例

Java.util.AbstractCollection.removeAll(Collection col) 方法用于从 AbstractCollection 中删除指定集合中存在的所有元素。

用法:

AbstractCollection.removeAll(Collection col)

参数：此方法接受一个强制参数 col，该参数是要从 AbstractCollection 中删除其元素的集合。

返回值：如果 AbstractCollection 完全由于操作而改变，则此方法返回 true，否则返回 False。

异常：如果指定的集合为空，该方法将抛出 NullPointerException。

以下示例程序旨在说明 Java.util.AbstractCollection.removeAll(Collection col) 方法：

程序1:


// Java code to illustrate removeAll()
import java.util.*;
  
public class AbstractCollectionDemo {
    public static void main(String args[])
    {
  
        // Creating an empty AbstractCollection
        AbstractCollection<String> collection
            = new ArrayList<String>();
  
        // Use add() method to add
        // elements in the AbstractCollection
        collection.add("Geeks");
        collection.add("for");
        collection.add("Geeks");
        collection.add("10");
        collection.add("20");
  
        // Output the AbstractCollection
        System.out.println("AbstractCollection:"
                           + collection);
  
        // Creating an empty AbstractCollection
        AbstractCollection<String> colcollection
            = new ArrayList<String>();
  
        // Use add() method to add
        // elements in the AbstractCollection
        colcollection.add("Geeks");
        colcollection.add("for");
        colcollection.add("Geeks");
  
        // Remove the head using remove()
        boolean changed
            = collection.removeAll(colcollection);
  
        // Print the result
        if (changed)
            System.out.println("Collection removed");
        else
            System.out.println("Collection not removed");
  
        // Print the final AbstractCollection
        System.out.println("Final AbstractCollection:"
                           + collection);
    }
}

输出：

AbstractCollection:[Geeks, for, Geeks, 10, 20]
Collection removed
Final AbstractCollection:[10, 20]

程序2:


// Java code to illustrate removeAll()
import java.util.*;
  
public class AbstractCollectionDemo {
    public static void main(String args[])
    {
  
        // Creating an empty AbstractCollection
        AbstractCollection<Integer> collection
            = new ArrayList<Integer>();
  
        // Use add() method to
        // add elements in the AbstractCollection
        collection.add(1);
        collection.add(2);
        collection.add(3);
        collection.add(10);
        collection.add(20);
  
        // Output the AbstractCollection
        System.out.println("AbstractCollection:"
                           + collection);
  
        // Creating an empty AbstractCollection
        AbstractCollection<Integer> colcollection
            = new ArrayList<Integer>();
  
        // Use add() method to add elements
        // in the AbstractCollection
        colcollection.add(30);
        colcollection.add(40);
        colcollection.add(50);
  
        // Remove the head using remove()
        boolean changed
            = collection.removeAll(colcollection);
  
        // Print the result
        if (changed)
            System.out.println("Collection removed");
        else
            System.out.println("Collection not removed");
  
        // Print the final AbstractCollection
        System.out.println("Final AbstractCollection:"
                           + collection);
    }
}

输出：

AbstractCollection:[1, 2, 3, 10, 20]
Collection not removed
Final AbstractCollection:[1, 2, 3, 10, 20]

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注：本文由纯净天空筛选整理自AnmoldeepKaur大神的英文原创作品 AbstractCollection removeAll() method in Java with Example。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。