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
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}
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