Map集合遍历方式(三种keySet、entrySet、forEach)
package Maptest01; import java.util.HashMap; import java.util.Map; import java.util.Set; /** * FileName: MapDemo02 * Author: lps * Date: 2022/4/14 11:59 * Sign:刘品水 Q:1944900433 */ public class MapDemo02 { public static void main(String[] args) { Map<String, Integer> maps = new HashMap<>();//一行经典代码 maps.put("刘品水",3); maps.put("枸杞",13); maps.put("Java",1); maps.put("Java",100); maps.put("手机",50); Set<String> keys = maps.keySet(); for (String key : keys) { Integer value = maps.get(key); System.out.println(key+"====>"+value); } System.out.println("==========="); Set<Map.Entry<String, Integer>> entries = maps.entrySet(); for (Map.Entry<String, Integer> entry : entries) { System.out.println(entry.getKey()+"===>"+entry.getValue()); } System.out.println("========"); //default void forEach(BiConsumer<? super K,? super V> action) 对此映射中的每个条目执行给定的操作,直到所有条目都被处理或操作引发异常。 maps.forEach((key, value) -> System.out.println(key+","+value)); // maps.forEach(new BiConsumer<String, Integer>() { // @Override // public void accept(String key, Integer value) { // System.out.println(key+","+value); // } // }); } }