java中如何创建及使用一个Map对象呢？

Map对象的定义

Map<K, V> map = new Map<K, V>();
K:代表map的key数据类型
V:代表map的value数据类型

Map <Integer, String> map = new HashMap<Integer, String>();
-----或-----
Map <Integer, String> map = new HashMap<>();

map.put(1, "java265.com-1");
map.put(2, "java265.com-2");
map.put(3, "java265.com-3");

//map中数值的获取
String a = map.get(1);
String b = map.get(2);
String c = map.get(3);

map中key遍历

Iterator keyIterator = map.keySet().iterator();
while (keyIterator.hasNext()) {
    Integer key = keyIterator.next();
    String value = map.get(key);
    System.out.println("key = " + key + "; value = " + value);
}

map中value遍历

Iterator valueIterator = map.values().iterator();
while(valueIterator.hasNext()) {
    System.out.println("value = " + valueIterator.next());
}

map中遍历方式二

for (Integer key : map.keySet()) {
    String value = map.get(key);
    System.out.println("key = " + key + "; value = " + value);
}

for (String s : map.values()) {
    System.out.println("value = " + s);
}