Map的迭代

public static void main(String[] args) {

        Map<String, Integer> map = new HashMap<String, Integer>();
        map.put("张三", 12);
        map.put("张三1", 121);
        map.put("张三2", 122);
        map.put("张三3", 123);
        map.put("张三4", 124);
        map.put("张三5", 125);
        map.put("张三6", 126);
        map.put("张三7", 127);

        // keySet
        Set<String> set = map.keySet();
        Iterator<String> it = set.iterator();
        while (it.hasNext()) {
            String key = it.next();
            System.out.println(key + "---" + map.get(key));
        }
        System.out.println("==============================================");
        // foreach 遍历keySet
        for (String string : map.keySet()) {
            System.out.println(string + "===" + map.get(string));
        }

        System.out.println("==============================================");

        // entrySet
        Set<Entry<String, Integer>> setenty = map.entrySet();
        Iterator<Entry<String, Integer>> ite = setenty.iterator();
        while (ite.hasNext()) {
            Entry<String, Integer> m = ite.next();
            System.out.println(m.getKey() + "---" + m.getValue());
        }
        
        System.out.println("==============================================");
        
        // foreach 遍历entrySet
        for (Entry<String, Integer> entry : map.entrySet()) {
            System.out.println(entry.getKey() + "===" + entry.getValue());
        }
    }