{"id":2260,"date":"2025-03-02T18:45:06","date_gmt":"2025-03-02T10:45:06","guid":{"rendered":"https:\/\/www.laixuexila.com\/?p=2260"},"modified":"2025-03-02T18:45:06","modified_gmt":"2025-03-02T10:45:06","slug":"java-iterator%ef%bc%88%e8%bf%ad%e4%bb%a3%e5%99%a8%ef%bc%89","status":"publish","type":"post","link":"https:\/\/www.laixuexila.com\/index.php\/2025\/03\/02\/java-iterator%ef%bc%88%e8%bf%ad%e4%bb%a3%e5%99%a8%ef%bc%89\/","title":{"rendered":"Java Iterator\uff08\u8fed\u4ee3\u5668\uff09"},"content":{"rendered":"\n

Iterator<\/code> \u662f Java \u96c6\u5408\u6846\u67b6\u4e2d\u7684\u4e00\u4e2a\u63a5\u53e3\uff0c\u63d0\u4f9b\u4e86\u4e00\u79cd\u904d\u5386\u96c6\u5408\uff08\u5982 List<\/code>\u3001Set<\/code> \u7b49\uff09\u5143\u7d20\u7684\u65b9\u5f0f\uff0c\u800c\u4e0d\u9700\u8981\u76f4\u63a5\u66b4\u9732\u96c6\u5408\u7684\u5185\u90e8\u7ed3\u6784\u3002Iterator<\/code> \u662f\u5b9e\u73b0\u96c6\u5408\u904d\u5386\u7684\u6807\u51c6\u65b9\u5f0f\uff0c\u901a\u8fc7 Iterator<\/code> \u53ef\u4ee5\u9010\u4e2a\u8bbf\u95ee\u96c6\u5408\u4e2d\u7684\u5143\u7d20\u3002<\/p>\n\n\n\n

1. Iterator \u63a5\u53e3\u7684\u57fa\u672c\u65b9\u6cd5<\/strong><\/h3>\n\n\n\n

Iterator<\/code> \u63a5\u53e3\u4e3b\u8981\u5b9a\u4e49\u4e86\u4ee5\u4e0b\u4e09\u4e2a\u65b9\u6cd5\uff1a<\/p>\n\n\n\n

    \n
  • hasNext()<\/code><\/strong>\uff1a\u5224\u65ad\u96c6\u5408\u4e2d\u662f\u5426\u8fd8\u6709\u4e0b\u4e00\u4e2a\u5143\u7d20\u3002<\/li>\n\n\n\n
  • next()<\/code><\/strong>\uff1a\u8fd4\u56de\u96c6\u5408\u4e2d\u7684\u4e0b\u4e00\u4e2a\u5143\u7d20\u3002\u5982\u679c\u6ca1\u6709\u4e0b\u4e00\u4e2a\u5143\u7d20\uff0c\u5219\u629b\u51fa NoSuchElementException<\/code>\u3002<\/li>\n\n\n\n
  • remove()<\/code><\/strong>\uff1a\u5220\u9664\u8fed\u4ee3\u5668\u5f53\u524d\u6307\u5411\u7684\u5143\u7d20\uff0c\u901a\u5e38\u662f\u901a\u8fc7 next()<\/code> \u83b7\u53d6\u7684\u5143\u7d20\u3002\u6b64\u65b9\u6cd5\u53ef\u9009\u3002<\/li>\n<\/ul>\n\n\n\n
    Iterator<E> iterator = collection.iterator();\nwhile (iterator.hasNext()) {\n    E element = iterator.next();\n    \/\/ \u5904\u7406\u5143\u7d20\n}<\/code><\/pre>\n\n\n\n
    2. \u4f7f\u7528 Iterator \u904d\u5386\u96c6\u5408<\/strong><\/h3>\n\n\n\n
    Iterator<\/code> \u63a5\u53e3\u6700\u5e38\u89c1\u7684\u7528\u6cd5\u662f\u7528\u6765\u904d\u5386\u96c6\u5408\u4e2d\u7684\u5143\u7d20\u3002\u901a\u8fc7\u4ee5\u4e0b\u6b65\u9aa4\u5b9e\u73b0\uff1a<\/p>\n\n\n\n
      \n
    1. \u4f7f\u7528\u96c6\u5408\u7684 iterator()<\/code> \u65b9\u6cd5\u83b7\u53d6\u8fed\u4ee3\u5668\u3002<\/li>\n\n\n\n
    2. \u4f7f\u7528 hasNext()<\/code> \u68c0\u67e5\u662f\u5426\u8fd8\u6709\u5143\u7d20\u3002<\/li>\n\n\n\n
    3. \u4f7f\u7528 next()<\/code> \u83b7\u53d6\u5f53\u524d\u5143\u7d20\u3002<\/li>\n\n\n\n
    4. \u5982\u679c\u9700\u8981\u5220\u9664\u5f53\u524d\u5143\u7d20\uff0c\u53ef\u4ee5\u8c03\u7528 remove()<\/code>\u3002<\/li>\n<\/ol>\n\n\n\n
      \u793a\u4f8b\uff1a\u904d\u5386 List<\/code> \u96c6\u5408<\/h4>\n\n\n\n
      import java.util.ArrayList;\nimport java.util.Iterator;\n\npublic class IteratorExample {\n    public static void main(String[] args) {\n        \/\/ \u521b\u5efa\u4e00\u4e2a List \u96c6\u5408\n        ArrayList<String> list = new ArrayList<>();\n        list.add(\"Apple\");\n        list.add(\"Banana\");\n        list.add(\"Cherry\");\n\n        \/\/ \u83b7\u53d6 Iterator \u5bf9\u8c61\n        Iterator<String> iterator = list.iterator();\n\n        \/\/ \u4f7f\u7528 Iterator \u904d\u5386\u96c6\u5408\n        while (iterator.hasNext()) {\n            String fruit = iterator.next();\n            System.out.println(fruit);\n        }\n    }\n}<\/code><\/pre>\n\n\n\n
      \u8f93\u51fa\uff1a<\/p>\n\n\n\n
      Apple\nBanana\nCherry<\/code><\/pre>\n\n\n\n
      \u793a\u4f8b\uff1a\u904d\u5386 Set<\/code> \u96c6\u5408<\/h4>\n\n\n\n
      import java.util.HashSet;\nimport java.util.Iterator;\n\npublic class IteratorExample {\n    public static void main(String[] args) {\n        \/\/ \u521b\u5efa\u4e00\u4e2a HashSet \u96c6\u5408\n        HashSet<String> set = new HashSet<>();\n        set.add(\"Apple\");\n        set.add(\"Banana\");\n        set.add(\"Cherry\");\n\n        \/\/ \u83b7\u53d6 Iterator \u5bf9\u8c61\n        Iterator<String> iterator = set.iterator();\n\n        \/\/ \u4f7f\u7528 Iterator \u904d\u5386\u96c6\u5408\n        while (iterator.hasNext()) {\n            String fruit = iterator.next();\n            System.out.println(fruit);\n        }\n    }\n}<\/code><\/pre>\n\n\n\n
      \u8f93\u51fa\uff1a<\/p>\n\n\n\n
      Apple\nBanana\nCherry<\/code><\/pre>\n\n\n\n
      3. remove()<\/code> \u65b9\u6cd5<\/strong><\/h3>\n\n\n\n
      remove()<\/code> \u65b9\u6cd5\u7528\u4e8e\u5220\u9664\u8fed\u4ee3\u5668\u5f53\u524d\u6307\u5411\u7684\u5143\u7d20\u3002\u8fd9\u4e2a\u65b9\u6cd5\u53ef\u4ee5\u5728\u904d\u5386\u8fc7\u7a0b\u4e2d\u5220\u9664\u5143\u7d20\uff0c\u4f46\u662f\u5b83\u53ea\u80fd\u5220\u9664\u901a\u8fc7 next()<\/code> \u8fd4\u56de\u7684\u5143\u7d20\u3002\u76f4\u63a5\u8c03\u7528 remove()<\/code> \u65f6\uff0c\u5982\u679c\u6ca1\u6709\u5148\u8c03\u7528 next()<\/code>\uff0c\u4f1a\u629b\u51fa IllegalStateException<\/code>\u3002<\/p>\n\n\n\n
      \u793a\u4f8b\uff1a\u4f7f\u7528 remove()<\/code> \u5220\u9664\u5143\u7d20<\/h4>\n\n\n\n
      import java.util.ArrayList;\nimport java.util.Iterator;\n\npublic class IteratorRemoveExample {\n    public static void main(String[] args) {\n        \/\/ \u521b\u5efa\u4e00\u4e2a List \u96c6\u5408\n        ArrayList<String> list = new ArrayList<>();\n        list.add(\"Apple\");\n        list.add(\"Banana\");\n        list.add(\"Cherry\");\n\n        \/\/ \u83b7\u53d6 Iterator \u5bf9\u8c61\n        Iterator<String> iterator = list.iterator();\n\n        \/\/ \u904d\u5386\u96c6\u5408\u5e76\u5220\u9664\u7279\u5b9a\u5143\u7d20\n        while (iterator.hasNext()) {\n            String fruit = iterator.next();\n            if (\"Banana\".equals(fruit)) {\n                iterator.remove(); \/\/ \u5220\u9664 \"Banana\"\n            }\n        }\n\n        \/\/ \u6253\u5370\u5220\u9664\u540e\u7684\u96c6\u5408\n        System.out.println(list);  \/\/ \u8f93\u51fa [Apple, Cherry]\n    }\n}<\/code><\/pre>\n\n\n\n
      \u8f93\u51fa\uff1a<\/p>\n\n\n\n
      [Apple, Cherry]<\/code><\/pre>\n\n\n\n
      4. Iterator \u7684\u7279\u70b9\u548c\u4f18\u52bf<\/strong><\/h3>\n\n\n\n
        \n
      • \u7edf\u4e00\u7684\u63a5\u53e3<\/strong>\uff1aIterator<\/code> \u63d0\u4f9b\u4e86\u7edf\u4e00\u7684\u904d\u5386\u96c6\u5408\u7684\u63a5\u53e3\uff0c\u652f\u6301\u96c6\u5408\u7684\u7edf\u4e00\u904d\u5386\u64cd\u4f5c\u3002<\/li>\n\n\n\n
      • \u4e0d\u66b4\u9732\u96c6\u5408\u7684\u5185\u90e8\u7ed3\u6784<\/strong>\uff1aIterator<\/code> \u5141\u8bb8\u904d\u5386\u96c6\u5408\u800c\u4e0d\u9700\u8981\u66b4\u9732\u96c6\u5408\u7684\u5185\u90e8\u5b9e\u73b0\uff0c\u589e\u5f3a\u4e86\u5c01\u88c5\u6027\u3002<\/li>\n\n\n\n
      • \u652f\u6301\u5220\u9664\u64cd\u4f5c<\/strong>\uff1aIterator<\/code> \u63d0\u4f9b\u4e86\u5728\u904d\u5386\u8fc7\u7a0b\u4e2d\u5220\u9664\u5143\u7d20\u7684\u529f\u80fd\uff0c\u8fd9\u5bf9\u4e8e\u67d0\u4e9b\u64cd\u4f5c\u975e\u5e38\u65b9\u4fbf\u3002<\/li>\n<\/ul>\n\n\n\n
        5. \u4e0e\u4f20\u7edf for \u5faa\u73af\u7684\u5bf9\u6bd4<\/strong><\/h3>\n\n\n\n
        \u4f20\u7edf\u7684 for \u5faa\u73af\uff08\u4f7f\u7528\u4e0b\u6807\uff09\u548c\u589e\u5f3a\u578b for \u5faa\u73af\uff08for-each<\/code>\uff09\u4e5f\u53ef\u4ee5\u7528\u6765\u904d\u5386\u96c6\u5408\uff0c\u4f46\u5b83\u4eec\u65e0\u6cd5\u5728\u904d\u5386\u8fc7\u7a0b\u4e2d\u5220\u9664\u5143\u7d20\u3002<\/p>\n\n\n\n
          \n
        • \u4f20\u7edf for \u5faa\u73af<\/strong>\uff1a\u53ea\u9002\u7528\u4e8e List<\/code>\uff0c\u4e0d\u9002\u7528\u4e8e Set<\/code>\u3002<\/li>\n\n\n\n
        • \u589e\u5f3a\u578b for \u5faa\u73af<\/strong>\uff08for-each<\/code>\uff09\uff1a\u9002\u7528\u4e8e List<\/code>\u3001Set<\/code> \u7b49\uff0c\u4f46\u65e0\u6cd5\u5220\u9664\u5143\u7d20\u3002<\/li>\n\n\n\n
        • Iterator<\/strong>\uff1a\u9002\u7528\u4e8e\u6240\u6709\u5b9e\u73b0\u4e86 Collection<\/code> \u63a5\u53e3\u7684\u7c7b\uff08\u5982 List<\/code>\u3001Set<\/code> \u7b49\uff09\uff0c\u5e76\u4e14\u53ef\u4ee5\u5728\u904d\u5386\u65f6\u5220\u9664\u5143\u7d20\u3002<\/li>\n<\/ul>\n\n\n\n
          \u4f7f\u7528 for-each<\/code> \u904d\u5386 List<\/code><\/h4>\n\n\n\n
          import java.util.ArrayList;\nimport java.util.List;\n\npublic class ForEachExample {\n    public static void main(String[] args) {\n        List<String> list = new ArrayList<>();\n        list.add(\"Apple\");\n        list.add(\"Banana\");\n        list.add(\"Cherry\");\n\n        \/\/ \u4f7f\u7528 for-each \u904d\u5386\n        for (String fruit : list) {\n            System.out.println(fruit);\n        }\n    }\n}<\/code><\/pre>\n\n\n\n
          \u4f7f\u7528 Iterator<\/code> \u904d\u5386 Set<\/code> \u5e76\u5220\u9664\u5143\u7d20<\/h4>\n\n\n\n
          import java.util.HashSet;\nimport java.util.Iterator;\nimport java.util.Set;\n\npublic class IteratorExample {\n    public static void main(String[] args) {\n        Set<String> set = new HashSet<>();\n        set.add(\"Apple\");\n        set.add(\"Banana\");\n        set.add(\"Cherry\");\n\n        \/\/ \u4f7f\u7528 Iterator \u904d\u5386\u5e76\u5220\u9664\u5143\u7d20\n        Iterator<String> iterator = set.iterator();\n        while (iterator.hasNext()) {\n            String fruit = iterator.next();\n            if (\"Banana\".equals(fruit)) {\n                iterator.remove(); \/\/ \u5220\u9664\u5143\u7d20\n            }\n        }\n\n        System.out.println(set); \/\/ \u8f93\u51fa [Apple, Cherry]\n    }\n}<\/code><\/pre>\n\n\n\n
          6. Iterator \u7684\u9002\u7528\u573a\u666f<\/strong><\/h3>\n\n\n\n
            \n
          • \u904d\u5386\u96c6\u5408<\/strong>\uff1a\u5f53\u9700\u8981\u904d\u5386\u96c6\u5408\u4e2d\u7684\u5143\u7d20\u65f6\uff0cIterator<\/code> \u662f\u4e00\u79cd\u901a\u7528\u7684\u904d\u5386\u65b9\u5f0f\u3002<\/li>\n\n\n\n
          • \u4fee\u6539\u96c6\u5408\u7ed3\u6784<\/strong>\uff1a\u5f53\u9700\u8981\u5728\u904d\u5386\u65f6\u5220\u9664\u6216\u66f4\u65b0\u5143\u7d20\u65f6\uff0cIterator<\/code> \u63d0\u4f9b\u4e86\u5b89\u5168\u7684\u65b9\u5f0f\uff08\u7279\u522b\u662f\u5220\u9664\u64cd\u4f5c\uff09\u3002<\/li>\n\n\n\n
          • \u8de8\u591a\u79cd\u96c6\u5408\u7c7b\u578b<\/strong>\uff1aIterator<\/code> \u53ef\u7528\u4e8e\u4efb\u4f55\u5b9e\u73b0\u4e86 Collection<\/code> \u63a5\u53e3\u7684\u96c6\u5408\uff0c\u9002\u5408\u7528\u4f5c\u8de8\u4e0d\u540c\u96c6\u5408\u7c7b\u578b\u7684\u904d\u5386\u5de5\u5177\u3002<\/li>\n<\/ul>\n\n\n\n
            7. \u6ce8\u610f\u4e8b\u9879<\/strong><\/h3>\n\n\n\n
              \n
            • \u8fed\u4ee3\u5668\u5728\u904d\u5386\u65f6\u5220\u9664\u5143\u7d20\u65f6\uff0c\u5fc5\u987b\u8c03\u7528 next()<\/code> \u65b9\u6cd5\uff0c\u4e14\u53ea\u80fd\u5220\u9664 next()<\/code> \u8fd4\u56de\u7684\u5f53\u524d\u5143\u7d20\u3002\u5982\u679c\u8c03\u7528 remove()<\/code> \u65f6\u6ca1\u6709\u8c03\u7528 next()<\/code>\uff0c\u4f1a\u629b\u51fa IllegalStateException<\/code>\u3002<\/li>\n\n\n\n
            • Iterator<\/code> \u4e0d\u652f\u6301\u5e76\u53d1\u4fee\u6539\u64cd\u4f5c\uff0c\u9664\u975e\u96c6\u5408\u662f\u7ebf\u7a0b\u5b89\u5168\u7684\u3002\u5373\u4e00\u4e2a\u7ebf\u7a0b\u904d\u5386\u65f6\uff0c\u53e6\u4e00\u4e2a\u7ebf\u7a0b\u4e0d\u5e94\u8be5\u4fee\u6539\u96c6\u5408\uff0c\u5426\u5219\u4f1a\u629b\u51fa ConcurrentModificationException<\/code>\u3002<\/li>\n<\/ul>\n\n\n\n
              \u5c0f\u7ed3<\/h3>\n\n\n\n
              Iterator<\/code> \u63d0\u4f9b\u4e86\u4e00\u79cd\u7edf\u4e00\u3001\u5b89\u5168\u7684\u65b9\u5f0f\u6765\u904d\u5386\u96c6\u5408\u4e2d\u7684\u5143\u7d20\uff0c\u5e76\u5141\u8bb8\u5728\u904d\u5386\u8fc7\u7a0b\u4e2d\u5220\u9664\u5143\u7d20\u3002\u5b83\u9002\u7528\u4e8e\u6240\u6709\u5b9e\u73b0\u4e86 Collection<\/code> \u63a5\u53e3\u7684\u7c7b\uff0c\u662f\u8fdb\u884c\u96c6\u5408\u904d\u5386\u65f6\u7684\u9996\u9009\u65b9\u5f0f\u3002\u66f4\u591a\u8be6\u7ec6\u5185\u5bb9\u8bf7\u5173\u6ce8\u5176\u4ed6\u76f8\u5173\u6587\u7ae0\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
              Iterator \u662f Java \u96c6\u5408\u6846\u67b6\u4e2d\u7684\u4e00\u4e2a\u63a5\u53e3\uff0c\u63d0\u4f9b\u4e86\u4e00\u79cd\u904d\u5386\u96c6\u5408\uff08\u5982 List\u3001Set \u7b49\uff09\u5143\u7d20\u7684\u65b9\u5f0f […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[68],"tags":[],"class_list":["post-2260","post","type-post","status-publish","format-standard","hentry","category-java"],"_links":{"self":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/2260","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/comments?post=2260"}],"version-history":[{"count":1,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/2260\/revisions"}],"predecessor-version":[{"id":2261,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/2260\/revisions\/2261"}],"wp:attachment":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media?parent=2260"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/categories?post=2260"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/tags?post=2260"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}