java中List、Set、Map、Properties集合的遍历方法总结

public class TransList {

public static void main(String[] args) {
TransList tl = new TransList();
List<String> lists = tl.getList();
tl.transList(lists);

}
//遍历List集合
public void transList(List<String> lists) {
//第一种方式：通过下标遍历
for (int i = 0; i < lists.size(); i++) {
System.out.println(lists.get(i));
}
//第二种方式：通过foreach遍历
for (String s : lists) {
System.out.println(s);
}
//第三种方式：Iterator迭代器遍历
Iterator<String> iterator = lists.iterator();
while (iterator.hasNext()) {
System.out.println(iterator.next());
}
}
//定义一个List集合并初始化
public List<String> getList() {
List<String> lists = new ArrayList<>();
lists.add("张三");
lists.add("李四");
lists.add("王五");
lists.add("刘麻子");
return lists;
}
}

public class TransSet {

public static void main(String[] args) {
TransSet ts = new TransSet();
Set<String> sets = ts.getSet();
ts.transSet(sets);

}
//遍历Set集合
public void transSet(Set<String> sets) {
//第一种方式：通过增强型for循环遍历
for (String s : sets) {
System.out.println(s);
}
//第二种方式：Iterator迭代器遍历
Iterator<String> iterator = sets.iterator();
while (iterator.hasNext()) {
System.out.println(iterator.next());
}
}
//定义一个Set集合并初始化
public Set<String> getSet() {
Set<String> sets = new HashSet<>();
sets.add("张三");
sets.add("李四");
sets.add("王五");
sets.add("刘麻子");
return sets;
}
}

public class TransMap {

public static void main(String[] args) {
TransMap tm = new TransMap();
Map<String, String> maps = tm.getMap();
tm.transMap(maps);

}
//遍历Map集合
public void transMap(Map<String, String> maps) {
//第一种方式：通过Set集合遍历<迭代Set
for (String key : maps.keySet()) {
System.out.println(key+"-->"+maps.get(key));
}
//第二种方式：通过Entry遍历<迭代Entry>
for (Entry<String, String> entry : maps.entrySet()) {
System.out.println(entry.getKey()+"---->"+entry.getValue());
}
}
//定义一个Map集合并初始化
public Map<String, String> getMap() {
Map<String, String> maps = new HashMap<>();
maps.put("1", "张三");
maps.put("2", "李四");
maps.put("3", "王五");
maps.put("4", "刘麻子");
return maps;
}
}

public class TransPro {

public static void main(String[] args) {
TransPro rp = new TransPro();
Properties pros = rp.getPro();
rp.transPro(pros);

}
//遍历Properties集合
public void transPro(Properties pros) {
//第一种方式：通过Set集合遍历<迭代Set
for (Object o : pros.keySet()) {
System.out.println(o+"-->"+pros.get(o));
}
//第二种方式：通过Entry遍历<迭代Entry>
for (Entry<Object, Object> entry : pros.entrySet()) {
System.out.println(entry.getKey()+"---->"+entry.getValue());
}
}
//定义一个Properties集合并初始化
public Properties getPro() {
Properties pros = new Properties();
pros.put("1", "张三");
pros.put("2", "李四");
pros.put("3", "王五");
pros.put("4", "刘麻子");
return pros;
}
}