java之map遍历

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java开发中常常会用到遍历，所以下边就列举四种map的遍历方法。

public class testMap { public static void main(String[] args) {
Map<Object, Object> map = new HashMap<Object, Object>();
map.put("01", "A");
map.put("02", "B");
map.put("03", "C");
// test1(map);
// test2(map);
// test3_1(map);
// test3_2(map);
test4(map);
} /**
* 遍历map方法一
*
* @param map
*/
public static void test1(Map<Object, Object> map) {
for (Entry<Object, Object> entry : map.entrySet()) {
System.out.println("Key = " + entry.getKey() + ", Value = "
+ entry.getValue());
}
} /**
* 遍历map方法二
*
* @param map
*/
public static void test2(Map<Object, Object> map) {
// 遍历map中的键
for (Object key : map.keySet()) {
System.out.println("Key = " + key);
} // 遍历map中的值
for (Object value : map.values()) {
System.out.println("Value = " + value);
}
} /**
* 遍历map方法三（非泛型）
*
* @param map
*/
public static void test3_1(Map<Object, Object> map) {
Iterator<Entry<Object, Object>> entries = map.entrySet().iterator();
Entry<Object, Object> entry;
while (entries.hasNext()) {
entry = entries.next();
System.out.println("Key = " + entry.getKey() + ", Value = "
+ entry.getValue());
}
} /**
* 遍历map方法三（泛型）
*
* @param map
*/
public static void test3_2(Map<Object, Object> map) {
Iterator entries = map.entrySet().iterator();
Entry entry;
while (entries.hasNext()) {
entry = (Entry) entries.next();
System.out.println("Key = " + entry.getKey() + ", Value = "
+ entry.getValue());
}
} /**
* 遍历map方法四
*
* @param map
*/
public static void test4(Map<Object, Object> map) {
for (Object key : map.keySet()) {
System.out.println("Key = " + key + ", Value = " + map.get(key));
}
}
}