hashmap 遍历
package practice31_2;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
public class hashmapkeyvalue2 {
public static void main(String[] args) {
HashMap<String, String> map = new HashMap<String,String>();
map.put("美利坚省","北美");
map.put("日本省","东亚");
map.put("俄罗斯省","欧洲");
map.put("加拿大省","南美");
map.put("南非省","非洲");
//遍历HASHMAP的三种方式
Set
for (String key : keySet) {
System.out.println(key + map.get(key));
}
System.out.println("***********************");
Iterator<String> iterator1 = map.keySet().iterator();
while (iterator1.hasNext()) {
String key = (String) iterator1.next();
System.out.println(key +map.get(key));
}
System.out.println("***********************");
Collection<String> values = map.values();
for (String val : values) {
System.out.println(val);
}
System.out.println("***********************");
Iterator<String> iterator2 = map.values().iterator();
while (iterator2.hasNext()) {
String values1 = (String) iterator2.next();
System.out.println(values1);
}
System.out.println("***********************");
Set<Entry<String, String>> entrySet = map.entrySet();
for (Entry<String, String> entry : entrySet) {
System.out.println(entry);
}
System.out.println("***********************");
Iterator<Entry<String, String>> iterator = map.entrySet().iterator();
while (iterator.hasNext()) {
Map.Entry<java.lang.String, java.lang.String> entry =
(Map.Entry<java.lang.String, java.lang.String>) iterator
.next();
System.out.println(entry);
}
}
}