Java 程序检查给定值是否存在于 HashMap 中
使用 containsValue() 方法检查给定值是否存在于 HashMap 中。
首先,让我们创建一个 HashMap 并添加一些元素——
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));
现在让我们检查给定的值是否存在。在此,我们检查值“800”——
hm.containsValue(800);
以下示例检查给定值是否存在于 HashMap 中——
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("Does key Bag exist in the HashMap = "+hm.containsKey("Bag")); System.out.println("Does value 800 exist in the HashMap = "+hm.containsValue(800)); } }
输出
Elements in HashMap... Frames: 800 Belt: 600 Wallet: 700 Bag: 1100 Sunglasses: 2000 Does key Bag exist in the HashMap = true Does value 800 exist in the HashMap = true
广告