Map集合的几种常见遍历方式

keySet()

for (String key : map.keySet()) {
    System.out.println(key);
}

values()

for (String value : map.values()) {
    System.out.println(value);
}

entrySet()

for (Map.Entry<String, String> entry : map.entrySet()) {
    String k = entry.getKey();
    String v = entry.getValue();
    System.out.println(k + " : " + v);
}

lambda

map.forEach((k, v) -> {
    System.out.println(k + " : " + v);
});

 Iterator

Iterator<Map.Entry<String, String>> entries = map.entrySet().iterator();
while (entries.hasNext()) {
    Map.Entry<String, String> entry = entries.next();
    String key = entry.getKey();
    String value = entry.getValue();
    System.out.println(key + " : " + value);
}