HashMap的迭代步骤

HashMap的迭代方法
HashMap的迭代方法

如果你只对Key感兴趣，你可以用keySet()

Map<String, Object> map = ...;for (String key : map.keySet()) {    // ...}

for (Object value : map.values()) {    // ...}

for (Map.Entry<String, Object> entry : map.entrySet()) {    String key = entry.getKey();    Object value = entry.getValue();    // ...}

public static void printMap(Map mp) {    Iterator it = mp.entrySet().iterator();    while (it.hasNext()) {        Map.Entry pairs = (Map.Entry)it.next();        System.out.println(pairs.getKey() + " = " + pairs.getValue());        it.remove(); // avoids a ConcurrentModificationException    }}