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  • 遍历集合

    遍历集合,使用Iterator。

    1.遍历HashMap:

     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     }

    输出结果:

    key:FF  values:22
    key:CC  values:21
    key:Tom  values:123

    2.遍历HashSet:

     1 void funcSet() {
     2         Set<String> set = new HashSet<>();
     3         set.add("Tom");
     4         set.add("CC");
     5         set.add("Naruto");
     6         Iterator<String> iterator = set.iterator();
     7         while (iterator.hasNext()) {
     8             String string = (String) iterator.next();
     9             System.out.println(string);
    10         }
    11     }

    输出:

    CC
    Tom
    Naruto

    3.遍历List:

     1 void funcList() {
     2         List<String> list = new ArrayList<>();
     3         list.add("Tom");
     4         list.add("CC");
     5         list.add("Narr");
     6         Iterator<String> iterator = list.iterator();
     7         while (iterator.hasNext()) {
     8             String string = (String) iterator.next();
     9             System.out.println(string);
    10         }
    11     }

    输出:

    Tom
    CC
    Narr

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  • 原文地址:https://www.cnblogs.com/mada0/p/4700305.html
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