在 Java HashMap 中獲取與指定鍵關聯的值
使用 get() 方法來獲取與指定鍵關聯的值。
這是我們的 HashMap 及其元素 -
// 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));
要獲取關聯的值, 鍵被設定為引數, 如下所示 -
hm.get("Frames")
上面, 鍵是 Frames, 我們正在獲取與它關聯的值。
以下示例演示瞭如何在 Java HashMap 中獲取與指定鍵關聯的值 -
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)); // Get a set of the entries Set set = hm.entrySet(); System.out.println("Elements in HashMap..."); // Get an iterator Iterator i = set.iterator(); // Display elements while(i.hasNext()) { Map.Entry me = (Map.Entry)i.next(); System.out.print(me.getKey() + ": "); System.out.println(me.getValue()); } System.out.println(); System.out.println("The value for key Frames in the HashMap = "+hm.get("Frames")); } }
輸出
Elements in HashMap... Frames: 800 Belt: 600 Wallet: 700 Bag: 1100 Sunglasses: 2000 The value for key Frames in the HashMap = 800
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