遍历集合

 1 void func() {
 2         HashMap<String, Integer> hashMap = new HashMap<>();
 3         hashMap.put("Tom", 123);
 4         hashMap.put("FF", 22);
 5         hashMap.put("CC", 21);
 6         Iterator<Entry<String, Integer>> iterator = hashMap.entrySet()
 7                 .iterator();
 8         while (iterator.hasNext()) {
 9             Map.Entry<String, Integer> entry = iterator.next();
10             System.out.println("key:" + entry.getKey() + "  values:"
11                     + entry.getValue());
12 
13         }
14     }