僅在鍵與給定值關聯的情況下,從此 HashMap 中移除鍵的 Java 程式


僅當鍵與給定值關聯時,才使用 remove() 方法來移除鍵。

假設以下內容是我們 HashMap −

// Create a hash map
HashMap hm = new HashMap();
// Put elements to the map
hm.put("Bag", new Integer(1100));
hm.put("Sunglasses", new Integer(2000));
hm.put("Frames", new Integer(800));
hm.put("Wallet", new Integer(700));
hm.put("Belt", new Integer(600));

在此,我們僅在與給定值 600 關聯的情況下,才刪除鍵“Belt” −

hm.remove("Belt", 600);

以下是僅在鍵與給定值關聯的情況下,移除鍵的一個示例 −

示例

 即時演示

import java.util.*;
public class Demo {
   public static void main(String args[]) {
      // Create a hash map
      HashMap hm = new HashMap();
      // Put elements to the map
      hm.put("Bag", new Integer(1100));
      hm.put("Sunglasses", new Integer(2000));
      hm.put("Frames", new Integer(800));
      hm.put("Wallet", new Integer(700));
      hm.put("Belt", new Integer(600));
      System.out.println("Elements in HashMap...");
      System.out.println(hm);
      // removing a key
      hm.remove("Wallet");
      System.out.println("
Updated HashMap after removing a key..."); System.out.println(hm); // removing a key from a HashMap only if it is associated with a given value hm.remove("Belt", 600); System.out.println("
Updated HashMap after removing a key associated with a given value..."); System.out.println(hm); } }

輸出

Elements in HashMap...
[Frames=800, Belt=600, Wallet=700, Bag=1100, Sunglasses=2000]

Updated HashMap after removing an key...
[Frames=800, Belt=600, Bag=1100, Sunglasses=2000]

Updated HashMap after removing a key associated with a given value...
{Frames=800, Bag=1100, Sunglasses=2000}

更新日期: 30-Jul-2019

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