{"id":2252,"date":"2025-03-02T18:39:37","date_gmt":"2025-03-02T10:39:37","guid":{"rendered":"https:\/\/www.laixuexila.com\/?p=2252"},"modified":"2025-03-02T18:39:37","modified_gmt":"2025-03-02T10:39:37","slug":"java-arraylist","status":"publish","type":"post","link":"https:\/\/www.laixuexila.com\/index.php\/2025\/03\/02\/java-arraylist\/","title":{"rendered":"Java ArrayList"},"content":{"rendered":"\n

ArrayList<\/code> \u662f Java \u96c6\u5408\u6846\u67b6\u4e2d\u975e\u5e38\u5e38\u7528\u7684\u4e00\u79cd\u5b9e\u73b0\u7c7b\uff0c\u5c5e\u4e8e List<\/strong> \u63a5\u53e3\u7684\u5b9e\u73b0\uff0c\u5b83\u57fa\u4e8e\u52a8\u6001\u6570\u7ec4\u6765\u5b9e\u73b0\u96c6\u5408\uff0c\u56e0\u6b64\u5177\u6709\u6309\u7d22\u5f15\u5feb\u901f\u8bbf\u95ee\u5143\u7d20\u7684\u7279\u70b9\u3002ArrayList<\/code> \u5141\u8bb8\u5b58\u50a8 \u91cd\u590d\u5143\u7d20<\/strong>\uff0c\u5e76\u4e14\u662f \u6709\u5e8f\u7684<\/strong>\uff0c\u5373\u5143\u7d20\u7684\u63d2\u5165\u987a\u5e8f\u4f1a\u88ab\u4fdd\u6301\u3002<\/p>\n\n\n\n

1. ArrayList \u7684\u57fa\u672c\u7279\u6027<\/strong><\/h3>\n\n\n\n
    \n
  • \u5927\u5c0f\u53ef\u53d8<\/strong>\uff1aArrayList<\/code> \u4f1a\u81ea\u52a8\u8c03\u6574\u6570\u7ec4\u7684\u5927\u5c0f\u4ee5\u9002\u5e94\u5143\u7d20\u7684\u589e\u51cf\u3002\u521d\u59cb\u5bb9\u91cf\u662f 10\uff0c\u5f53 ArrayList<\/code> \u4e2d\u7684\u5143\u7d20\u8d85\u8fc7\u5f53\u524d\u5bb9\u91cf\u65f6\uff0c\u5b83\u4f1a\u6269\u5bb9\uff08\u901a\u5e38\u662f\u6269\u5c55\u4e3a\u539f\u6765\u5927\u5c0f\u7684 1.5 \u500d\uff09\u3002<\/li>\n\n\n\n
  • \u652f\u6301\u968f\u673a\u8bbf\u95ee<\/strong>\uff1a\u901a\u8fc7\u7d22\u5f15\u8bbf\u95ee\u5143\u7d20\u7684\u65f6\u95f4\u590d\u6742\u5ea6\u662f O(1)\u3002<\/li>\n\n\n\n
  • \u4e0d\u652f\u6301\u7ebf\u7a0b\u5b89\u5168<\/strong>\uff1aArrayList<\/code> \u4e0d\u662f\u7ebf\u7a0b\u5b89\u5168\u7684\uff0c\u5982\u679c\u591a\u4e2a\u7ebf\u7a0b\u5e76\u53d1\u4fee\u6539\u540c\u4e00\u4e2a ArrayList<\/code>\uff0c\u9700\u8981\u989d\u5916\u7684\u540c\u6b65\u5904\u7406\u3002<\/li>\n\n\n\n
  • \u5141\u8bb8\u5b58\u50a8 null<\/code><\/strong>\uff1aArrayList<\/code> \u53ef\u4ee5\u5b58\u50a8 null<\/code> \u5143\u7d20\u3002<\/li>\n<\/ul>\n\n\n\n

    2. ArrayList \u7684\u5e38\u7528\u6784\u9020\u51fd\u6570<\/strong><\/h3>\n\n\n\n
    \/\/ \u9ed8\u8ba4\u6784\u9020\u51fd\u6570\uff0c\u521d\u59cb\u5bb9\u91cf\u4e3a 10\nArrayList<E> list = new ArrayList<>();\n\n\/\/ \u6307\u5b9a\u521d\u59cb\u5bb9\u91cf\nArrayList<E> list = new ArrayList<>(int initialCapacity);\n\n\/\/ \u57fa\u4e8e\u53e6\u4e00\u4e2a\u96c6\u5408\u521b\u5efa ArrayList\nArrayList<E> list = new ArrayList<>(Collection<? extends E> c);<\/code><\/pre>\n\n\n\n
    3. ArrayList \u5e38\u7528\u65b9\u6cd5<\/strong><\/h3>\n\n\n\n
    3.1 \u6dfb\u52a0\u5143\u7d20<\/strong><\/h4>\n\n\n\n
      \n
    • add(E e)<\/code>\uff1a\u5c06\u5143\u7d20\u6dfb\u52a0\u5230\u5217\u8868\u7684\u672b\u5c3e\u3002<\/li>\n\n\n\n
    • add(int index, E element)<\/code>\uff1a\u5728\u6307\u5b9a\u7684\u7d22\u5f15\u4f4d\u7f6e\u63d2\u5165\u5143\u7d20\u3002<\/li>\n<\/ul>\n\n\n\n
      ArrayList<String> list = new ArrayList<>();\nlist.add(\"Apple\");\nlist.add(\"Banana\");\nlist.add(1, \"Orange\"); \/\/ \u5728\u7d22\u5f15 1 \u63d2\u5165 \"Orange\"<\/code><\/pre>\n\n\n\n
      3.2 \u5220\u9664\u5143\u7d20<\/strong><\/h4>\n\n\n\n
        \n
      • remove(Object o)<\/code>\uff1a\u5220\u9664\u7b2c\u4e00\u6b21\u51fa\u73b0\u7684\u6307\u5b9a\u5143\u7d20\u3002<\/li>\n\n\n\n
      • remove(int index)<\/code>\uff1a\u5220\u9664\u6307\u5b9a\u4f4d\u7f6e\u7684\u5143\u7d20\u3002<\/li>\n\n\n\n
      • clear()<\/code>\uff1a\u5220\u9664\u6240\u6709\u5143\u7d20\u3002<\/li>\n<\/ul>\n\n\n\n
        list.remove(\"Banana\"); \/\/ \u5220\u9664 \"Banana\"\nlist.remove(0);        \/\/ \u5220\u9664\u7d22\u5f15\u4e3a 0 \u7684\u5143\u7d20\nlist.clear();          \/\/ \u6e05\u7a7a ArrayList<\/code><\/pre>\n\n\n\n
        3.3 \u8bbf\u95ee\u5143\u7d20<\/strong><\/h4>\n\n\n\n
          \n
        • get(int index)<\/code>\uff1a\u83b7\u53d6\u6307\u5b9a\u7d22\u5f15\u4f4d\u7f6e\u7684\u5143\u7d20\u3002<\/li>\n\n\n\n
        • set(int index, E element)<\/code>\uff1a\u66ff\u6362\u6307\u5b9a\u7d22\u5f15\u4f4d\u7f6e\u7684\u5143\u7d20\u3002<\/li>\n<\/ul>\n\n\n\n
          String fruit = list.get(1); \/\/ \u83b7\u53d6\u7d22\u5f15\u4e3a 1 \u7684\u5143\u7d20\nlist.set(1, \"Grapes\");     \/\/ \u66ff\u6362\u7d22\u5f15\u4e3a 1 \u7684\u5143\u7d20<\/code><\/pre>\n\n\n\n
          3.4 \u67e5\u8be2\u5143\u7d20<\/strong><\/h4>\n\n\n\n
            \n
          • contains(Object o)<\/code>\uff1a\u68c0\u67e5\u5217\u8868\u662f\u5426\u5305\u542b\u67d0\u4e2a\u5143\u7d20\u3002<\/li>\n\n\n\n
          • indexOf(Object o)<\/code>\uff1a\u8fd4\u56de\u6307\u5b9a\u5143\u7d20\u9996\u6b21\u51fa\u73b0\u7684\u7d22\u5f15\uff0c\u5982\u679c\u6ca1\u6709\u627e\u5230\u8fd4\u56de -1\u3002<\/li>\n\n\n\n
          • size()<\/code>\uff1a\u8fd4\u56de ArrayList<\/code> \u4e2d\u7684\u5143\u7d20\u4e2a\u6570\u3002<\/li>\n\n\n\n
          • isEmpty()<\/code>\uff1a\u5224\u65ad ArrayList<\/code> \u662f\u5426\u4e3a\u7a7a\u3002<\/li>\n<\/ul>\n\n\n\n
            boolean containsApple = list.contains(\"Apple\"); \/\/ \u68c0\u67e5\u662f\u5426\u5305\u542b \"Apple\"\nint index = list.indexOf(\"Grapes\"); \/\/ \u83b7\u53d6 \"Grapes\" \u7684\u7d22\u5f15\nint size = list.size(); \/\/ \u83b7\u53d6 ArrayList \u7684\u5927\u5c0f\nboolean isEmpty = list.isEmpty(); \/\/ \u5224\u65ad\u662f\u5426\u4e3a\u7a7a<\/code><\/pre>\n\n\n\n
            3.5 \u904d\u5386\u5143\u7d20<\/strong><\/h4>\n\n\n\n
              \n
            • \u4f7f\u7528 for-each<\/strong> \u5faa\u73af\uff1a<\/li>\n<\/ul>\n\n\n\n
              for (String fruit : list) {\n    System.out.println(fruit);\n}<\/code><\/pre>\n\n\n\n
                \n
              • \u4f7f\u7528 Iterator<\/strong>\uff1a<\/li>\n<\/ul>\n\n\n\n
                Iterator<String> iterator = list.iterator();\nwhile (iterator.hasNext()) {\n    System.out.println(iterator.next());\n}<\/code><\/pre>\n\n\n\n
                  \n
                • \u4f7f\u7528 for<\/strong> \u5faa\u73af\uff1a<\/li>\n<\/ul>\n\n\n\n
                  for (int i = 0; i < list.size(); i++) {\n    System.out.println(list.get(i));\n}<\/code><\/pre>\n\n\n\n
                  3.6 \u8f6c\u6362\u4e3a\u6570\u7ec4<\/strong><\/h4>\n\n\n\n
                    \n
                  • toArray()<\/code>\uff1a\u5c06 ArrayList<\/code> \u8f6c\u6362\u4e3a\u6570\u7ec4\u3002<\/li>\n<\/ul>\n\n\n\n
                    Object[] array = list.toArray();<\/code><\/pre>\n\n\n\n
                      \n
                    • toArray(T[] a)<\/code>\uff1a\u5c06 ArrayList<\/code> \u8f6c\u6362\u4e3a\u6307\u5b9a\u7c7b\u578b\u7684\u6570\u7ec4\u3002<\/li>\n<\/ul>\n\n\n\n
                      String[] array = list.toArray(new String[0]);<\/code><\/pre>\n\n\n\n
                      3.7 \u5176\u4ed6\u5e38\u7528\u65b9\u6cd5<\/strong><\/h4>\n\n\n\n
                        \n
                      • removeAll(Collection<?> c)<\/code>\uff1a\u5220\u9664\u5217\u8868\u4e2d\u6240\u6709\u4e0e\u7ed9\u5b9a\u96c6\u5408 c<\/code> \u76f8\u540c\u7684\u5143\u7d20\u3002<\/li>\n\n\n\n
                      • retainAll(Collection<?> c)<\/code>\uff1a\u4fdd\u7559\u5217\u8868\u4e2d\u6240\u6709\u4e0e\u7ed9\u5b9a\u96c6\u5408 c<\/code> \u76f8\u540c\u7684\u5143\u7d20\u3002<\/li>\n\n\n\n
                      • subList(int fromIndex, int toIndex)<\/code>\uff1a\u8fd4\u56de\u6307\u5b9a\u8303\u56f4\u7684\u5b50\u5217\u8868\uff08\u4e0d\u5305\u62ec toIndex<\/code>\uff09\u3002<\/li>\n\n\n\n
                      • ensureCapacity(int minCapacity)<\/code>\uff1a\u786e\u4fdd\u5217\u8868\u6709\u8db3\u591f\u7684\u5bb9\u91cf\u6765\u5bb9\u7eb3\u81f3\u5c11 minCapacity<\/code> \u4e2a\u5143\u7d20\u3002<\/li>\n<\/ul>\n\n\n\n
                        4. ArrayList \u7684\u6027\u80fd<\/strong><\/h3>\n\n\n\n
                          \n
                        • \u8bbf\u95ee\u5143\u7d20<\/strong>\uff1a\u7531\u4e8e ArrayList<\/code> \u662f\u57fa\u4e8e\u52a8\u6001\u6570\u7ec4\u5b9e\u73b0\u7684\uff0c\u83b7\u53d6\u5143\u7d20\u662f O(1) \u7684\u65f6\u95f4\u590d\u6742\u5ea6\u3002<\/li>\n\n\n\n
                        • \u6dfb\u52a0\u5143\u7d20<\/strong>\uff1a\u5982\u679c\u662f\u5728\u672b\u5c3e\u6dfb\u52a0\u5143\u7d20\uff0c\u65f6\u95f4\u590d\u6742\u5ea6\u4e3a O(1)\uff0c\u4f46\u662f\u5f53\u9700\u8981\u6269\u5bb9\u65f6\uff08\u5143\u7d20\u6570\u91cf\u8d85\u8fc7\u5f53\u524d\u5bb9\u91cf\uff09\uff0c\u65f6\u95f4\u590d\u6742\u5ea6\u662f O(n)\u3002<\/li>\n\n\n\n
                        • \u63d2\u5165\u548c\u5220\u9664\u5143\u7d20<\/strong>\uff1a\u5728\u4e2d\u95f4\u6216\u5934\u90e8\u63d2\u5165\u6216\u5220\u9664\u5143\u7d20\u65f6\uff0c\u9700\u8981\u79fb\u52a8\u5176\u4ed6\u5143\u7d20\uff0c\u56e0\u6b64\u65f6\u95f4\u590d\u6742\u5ea6\u4e3a O(n)\u3002<\/li>\n<\/ul>\n\n\n\n
                          5. \u4f7f\u7528 ArrayList \u7684\u573a\u666f<\/strong><\/h3>\n\n\n\n
                            \n
                          • \u968f\u673a\u8bbf\u95ee<\/strong>\uff1aArrayList<\/code> \u5728\u9700\u8981\u9891\u7e41\u901a\u8fc7\u7d22\u5f15\u8bbf\u95ee\u5143\u7d20\u7684\u573a\u666f\u4e2d\u8868\u73b0\u4f18\u5f02\u3002<\/li>\n\n\n\n
                          • \u5143\u7d20\u4e2a\u6570\u53d8\u5316\u8f83\u5c11<\/strong>\uff1a\u5f53\u5143\u7d20\u4e2a\u6570\u53d8\u5316\u8f83\u5c11\u65f6\uff0c\u4f7f\u7528 ArrayList<\/code> \u5f88\u65b9\u4fbf\uff0c\u56e0\u4e3a\u5b83\u7684\u67e5\u8be2\u6548\u7387\u9ad8\u3002<\/li>\n\n\n\n
                          • \u6392\u5e8f\u64cd\u4f5c<\/strong>\uff1a\u7531\u4e8e ArrayList<\/code> \u5141\u8bb8\u8bbf\u95ee\u6240\u6709\u5143\u7d20\uff0c\u56e0\u6b64\u53ef\u4ee5\u901a\u8fc7\u96c6\u5408\u7c7b\u4e2d\u7684 sort()<\/code> \u65b9\u6cd5\u5feb\u901f\u6392\u5e8f\u3002<\/li>\n<\/ul>\n\n\n\n
                            6. \u7ebf\u7a0b\u5b89\u5168\u95ee\u9898<\/strong><\/h3>\n\n\n\n
                            ArrayList<\/code> \u9ed8\u8ba4\u4e0d\u662f\u7ebf\u7a0b\u5b89\u5168\u7684\u3002\u5982\u679c\u5728\u591a\u7ebf\u7a0b\u73af\u5883\u4e2d\u540c\u65f6\u8bbf\u95ee\u548c\u4fee\u6539 ArrayList<\/code>\uff0c\u5219\u53ef\u80fd\u4f1a\u5bfc\u81f4\u6570\u636e\u4e0d\u4e00\u81f4\u95ee\u9898\u3002\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0c\u53ef\u4ee5\u4f7f\u7528\uff1a<\/p>\n\n\n\n
                              \n
                            • Collections.synchronizedList()<\/code>\uff1a\u5c06 ArrayList<\/code> \u5305\u88c5\u6210\u7ebf\u7a0b\u5b89\u5168\u7684\u5217\u8868\u3002<\/li>\n\n\n\n
                            • CopyOnWriteArrayList<\/code>\uff1a\u9002\u7528\u4e8e\u5199\u64cd\u4f5c\u8f83\u5c11\u7684\u591a\u7ebf\u7a0b\u73af\u5883\uff0c\u5b83\u4f1a\u5728\u6bcf\u6b21\u4fee\u6539\u65f6\u590d\u5236\u6574\u4e2a\u6570\u7ec4\u3002<\/li>\n<\/ul>\n\n\n\n
                              List<String> synchronizedList = Collections.synchronizedList(new ArrayList<>());<\/code><\/pre>\n\n\n\n
                              7. ArrayList \u4e0e LinkedList \u7684\u6bd4\u8f83<\/strong><\/h3>\n\n\n\n
                              \u7279\u6027<\/th>ArrayList<\/code><\/th>LinkedList<\/code><\/th><\/tr><\/thead>
                              \u5e95\u5c42\u5b9e\u73b0<\/strong><\/td>\u52a8\u6001\u6570\u7ec4<\/td>\u53cc\u5411\u94fe\u8868<\/td><\/tr>
                              \u968f\u673a\u8bbf\u95ee<\/strong><\/td>\u5feb\u901f O(1)<\/td>\u6162 O(n)<\/td><\/tr>
                              \u63d2\u5165\/\u5220\u9664\u64cd\u4f5c<\/strong><\/td>\u6162 O(n)\uff0c\u5c24\u5176\u662f\u4e2d\u95f4\u4f4d\u7f6e<\/td>\u5feb O(1)\uff0c\u5728\u5934\u5c3e\u63d2\u5165\u548c\u5220\u9664\u8f83\u5feb<\/td><\/tr>
                              \u5185\u5b58\u5360\u7528<\/strong><\/td>\u5185\u5b58\u5360\u7528\u8f83\u5c0f<\/td>\u6bcf\u4e2a\u8282\u70b9\u989d\u5916\u5b58\u50a8\u524d\u540e\u8282\u70b9\u5f15\u7528<\/td><\/tr>
                              \u9002\u7528\u573a\u666f<\/strong><\/td>\u9891\u7e41\u67e5\u8be2\uff0c\u5c11\u91cf\u63d2\u5165\u5220\u9664\u64cd\u4f5c<\/td>\u9891\u7e41\u63d2\u5165\u5220\u9664\uff0c\u5c24\u5176\u662f\u5934\u5c3e\u4f4d\u7f6e\u64cd\u4f5c<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
                              \u5c0f\u7ed3<\/h3>\n\n\n\n
                              ArrayList<\/code> \u662f\u4e00\u4e2a\u7075\u6d3b\u4e14\u9ad8\u6548\u7684\u96c6\u5408\u7c7b\uff0c\u9002\u7528\u4e8e\u9700\u8981\u5feb\u901f\u968f\u673a\u8bbf\u95ee\u548c\u8f83\u5c11\u4fee\u6539\u7684\u573a\u666f\u3002\u5b83\u662f Java \u96c6\u5408\u6846\u67b6\u4e2d\u6700\u5e38\u7528\u7684\u7c7b\u4e4b\u4e00\uff0c\u5bf9\u4e8e\u9700\u8981\u9891\u7e41\u8bfb\u53d6\u4f46\u8f83\u5c11\u63d2\u5165\u6216\u5220\u9664\u5143\u7d20\u7684\u5e94\u7528\u573a\u666f\u975e\u5e38\u5408\u9002\u3002\u5982\u679c\u9700\u8981\u66f4\u9891\u7e41\u7684\u63d2\u5165\u548c\u5220\u9664\u64cd\u4f5c\uff0c\u53ef\u80fd\u9700\u8981\u8003\u8651 LinkedList<\/code>\u3002\u66f4\u591a\u8be6\u7ec6\u5185\u5bb9\u8bf7\u5173\u6ce8\u5176\u4ed6\u76f8\u5173\u6587\u7ae0\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
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