public class Pet {
public static void main(String[] args) {
Map pet=
new HashMap();
pet.put(
"Q仔",
"企鹅");
pet.put(
"欧欧",
"雪纳瑞");
pet.put(
"汤姆",
"猫");
pet.put(
"杰瑞",
"老鼠");
Set keys=pet.keySet();
Iterator it=keys.iterator();
while (it.hasNext()){ //条件可以按照中文翻译 他是否有下一个
String key=(String)it.next();
String pet1=(String)pet.get(key);
System.
out.println(key+
" "+pet1);
}
System.
out.println();
for (
int i =
0; i <keys.size() ; i++) {
String key= (String) keys.toArray()[i];
String pet1=(String)pet.get(key);
System.
out.println(key+
" "+pet1);
}
System.
out.println();
for (Object key:keys) {//keys=for循环的条件(
int i =
0; i <keys.size() ; i++)
//定义Object类型，得到对象key =for循环中的String key= (String) keys.toArray()[i];
String pet1=(String)pet.get(key);
System.
out.println(key+
" "+pet1);
}
}
}
