Map的两种遍历

Posted 2020-10-27

import java.util.HashMap;
import java.util.Map;
import java.util.Set;

public class MapDemo {
public static void main(String args[]){
Map<String,String> map = new HashMap<String,String>();
map.put("1","张三");
map.put("2","李四");
map.put("3","王五");

    //keySet()遍历
    /*Set<String> keys =  map.keySet();
    for (String  key:keys) {
         String value =  map.get(key);
         System.out.println(key+"  "+value);
    }*/

    //entrySet()遍历
    Set<Map.Entry<String,String>> entrys = map.entrySet();
    for (Map.Entry<String,String> entry:entrys) {
        String key =  entry.getKey();
        String value = entry.getValue();
        System.out.println(key+" "+value);
    }
}

}