Java 中的 ConcurrentSkipListMap remove()方法,示例

原文:https://www . geeksforgeeks . org/concurrentskiplistmap-remove-method-in-Java-with-examples/

java . util . concurrentskiplistmapremove() 方法是 Java 中的一个内置函数,它从该映射中删除指定键的映射。如果没有该特定键的映射,则方法返回 null。执行此方法后,地图的大小会减小。

语法:

ConcurrentSkipListMap.remove(Object ob)

参数:该函数接受单个强制参数 ob ,该参数指定要删除其映射的键。

返回值:该函数返回与指定键相关联的前一个值,如果该键没有映射,则返回空值。

下面的程序说明了上面的方法:

// Java Program Demonstrate remove()
// method of ConcurrentSkipListMap

import java.util.concurrent.*;

class GFG {
    public static void main(String[] args)
    {

        // Initializing the map
        ConcurrentSkipListMap<Integer, Integer>
            mpp = new ConcurrentSkipListMap<Integer,
                                            Integer>();

        // Adding elements to this map
        for (int i = 1; i <= 5; i++)
            mpp.put(i, i);
        // remove() operation on the map
        mpp.remove(1);

        System.out.println("After remove(): " + mpp);
    }
}

输出:

After remove(): {2=2, 3=3, 4=4, 5=5}

程序二:

// Java Program Demonstrate remove()
// method of ConcurrentSkipListMap

import java.util.concurrent.*;

class GFG {
    public static void main(String[] args)
    {

        // Initializing the map
        ConcurrentSkipListMap<Integer, Integer>
            mpp = new ConcurrentSkipListMap<Integer,
                                            Integer>();

        // Adding elements to this map
        for (int i = 1; i <= 5; i++)
            mpp.put(i, i);
        // remove() operation on the map
        mpp.remove(5);

        System.out.println("After remove(): " + mpp);
    }
}

输出:

After remove(): {1=1, 2=2, 3=3, 4=4}

参考:https://docs . Oracle . com/javase/8/docs/API/Java/util/concurrentskiplistmap . html # remove-Java . lang . object-