{"id":397,"date":"2022-11-24T11:21:45","date_gmt":"2022-11-24T03:21:45","guid":{"rendered":"https:\/\/iichen.cn\/?p=397"},"modified":"2022-11-24T11:21:45","modified_gmt":"2022-11-24T03:21:45","slug":"kotlin-%e4%b8%8d%e5%8f%98%e5%9e%8b%e3%80%81%e5%8d%8f%e5%8f%98%e3%80%81%e9%80%86%e5%8f%98","status":"publish","type":"post","link":"https:\/\/iichen.cn\/?p=397","title":{"rendered":"Kotlin-\u4e0d\u53d8\u578b\u3001\u534f\u53d8\u3001\u9006\u53d8"},"content":{"rendered":"
1. \u5b50\u7c7b\u578b<\/h5>\n

\n \u4efb\u4f55\u65f6\u5019\uff0c\u5982\u679c\u8981\u4f7f\u7528 \u7c7b\u578bA \u7684\u503c\uff0c\u90fd\u80fd\u7528 \u7c7b\u578bB \u7684\u503c\u4f5c\u4e3a\u66ff\u6362\uff08\u5f53\u505a A \u7684\u503c\uff09\uff0c\u79f0 B \u662f A \u7684\u5b50\u7c7b\u578b\u3002\n<\/p><\/blockquote>\n

2. \u6cdb\u578b\u4e2d\u7684\u5b50\u7c7b\u578b<\/h5>\n

\u5982\u679cList\u8981\u6210\u4e3aList\u7684\u5b50\u7c7b\u5c31\u5fc5\u987b\u6ee1\u8db3\u4e0b\u9762\u4e24\u4e2a\u6761\u4ef6\uff1a
\n1. List\u4e2d\u65b9\u6cd5\u63a5\u6536\u53c2\u6570\u7684\u8303\u56f4 \u4e0d\u5f97\u5c0f\u4e8e List\u7684\u65b9\u6cd5
\n2. List\u4e2d\u65b9\u6cd5\u8fd4\u56de\u503c\u7684\u8303\u56f4 \u4e0d\u5f97\u5927\u4e8e List\u7684\u65b9\u6cd5<\/p>\n

\/\/ List\u5e26\u6cdb\u578b\u7684\u5b9a\u4e49\npublic interface List<E> extends Collection<E> {\n    boolean add(E e);\n    E get(int index);\n}\n\n\/\/ List<String>\u5b9a\u4e49\u5982\u4e0b:\npublic interface List<String> extends Collection<String> {\n    boolean add(String e);\n    String get(int index);\n}\n\n\/\/ List<CharSequence>\u5b9a\u4e49\u5982\u4e0b:\npublic interface List<CharSequence> extends Collection<String> {\n    boolean add(CharSequence e);\n    CharSequence get(int index);\n}\n<\/code><\/pre>\n
\u867d\u7136String get(int index);\u8fd4\u56de\u503c\u7684\u8303\u56f4\u6bd4CharSequence get(int index);\u5c0f\uff0c\u6ee1\u8db3\u4e86\u7b2c\u4e8c\u4e2a\u6761\u4ef6\u3002
\n\u4f46boolean add(String e);\u63a5\u6536\u53c2\u6570\u7684\u8303\u56f4\u660e\u663e\u6bd4boolean add(CharSequence e);\u8981\u5c0f\uff0c\u4e0d\u6ee1\u8db3\u7b2c\u4e00\u4e2a\u6761\u4ef6\u3002\u4e0d\u53d8\u578b
\n\u6240\u4ee5List\u4e0d\u662fList\u7684\u5b50\u7c7b\u578b<\/p>\n
\n  \u4e0d\u53d8\u578b\uff1aType1\u662fType2\u7684\u5b50\u7c7b\uff0c\u5982\u679cA\u548cA\u4e0d\u5b58\u5728\u7236\u5b50\u5173\u7cfb\uff0c\u5219\u79f0 \u7c7bA \u5728\u7c7b\u578b\u53c2\u6570\u4e0a\u662f\u4e0d\u53d8\u578b\u7684<\/strong><\/p>\n
  \u534f\u53d8: \u5f53\u7c7b\u578b\u53c2\u6570\u53d8\u5f97\u66f4\u5177\u4f53\u65f6\uff0c\u7c7b\u4e5f\u53d8\u5f97\u66f4\u5177\u4f53\u3002\u5f53\u7c7b\u578b\u53c2\u6570\u53d8\u5f97\u66f4\u62bd\u8c61\u65f6\uff0c\u7c7b\u4e5f\u53d8\u5f97\u66f4\u62bd\u8c61<\/strong>
\n  \u5373\u5c06\u4e0a\u8ff0\u7684add\/set\u65b9\u6cd5\u5c4f\u853d \u53ea\u80fdget\/\u53d6\u8fd4\u56de\u503c\uff0ckotlin\u4f7f\u7528out\u5173\u952e\u8bcd class MyList<out T>{ ... }<\/code><\/p>\n
  \u9006\u53d8: \u5f53\u7c7b\u578b\u53c2\u6570\u53d8\u5f97\u66f4\u5177\u4f53\u65f6\uff0c\u7c7b\u5374\u53d8\u5f97\u66f4\u62bd\u8c61\u3002\u5f53\u7c7b\u578b\u53c2\u6570\u53d8\u5f97\u66f4\u62bd\u8c61\u65f6\uff0c\u7c7b\u5374\u53d8\u5f97\u66f4\u5177\u4f53<\/strong>
\n  \u5373\u5c06\u4e0a\u8ff0\u7684get\/\u53d6\u8fd4\u56de\u503c\u5c4f\u853d\uff0c\u4fdd\u7559add\/set\u65b9\u6cd5\uff0ckotlin\u4f7f\u7528in\u5173\u952e\u8bcd class MyList<in T>{ ... }<\/code><\/p>\n
  Java\u6210\u4e3aPECS\u539f\u5219\uff0c\u534f\u53d8\uff1a<? extends T>, \u9006\u53d8\uff1a<? super T>
\n  kotlin\u5219POCI\u539f\u5219\n<\/p><\/blockquote>\n
3. \u6295\u5f71<\/h5>\n\n\n\n\n\n\n\n
\u6295\u5f71\u7c7b\u578b<\/th>\n\u6295\u5f71\u5b9e\u4f8b<\/th>\n\u53d8\u578b<\/th>\n\u7ee7\u627f\u5173\u7cfb<\/th>\n\u9650\u5236<\/th>\n<\/tr>\n<\/thead>\n
out\u6295\u5f71<\/td>\nGroup< out Animal ><\/td>\n\u534f\u53d8<\/td>\nGroup< Dog > \u662f Group< out Animal ><\/td>\n\u5b50\u7c7b\u7c7b\u578b\u53c2\u6570\u4e0d\u80fd\u4f5c\u4e3a\u65b9\u6cd5\u53c2\u6570<\/td>\n<\/tr>\n
in\u6295\u5f71<\/td>\nGroup< in Animal ><\/td>\n\u9006\u53d8<\/td>\nGroup< in Animal > \u662f Group< Dog ><\/td>\n\u5b50\u7c7b\u7c7b\u578b\u53c2\u6570\u4e0d\u80fd\u4f5c\u4e3a\u65b9\u6cd5\u8fd4\u56de\u503c<\/td>\n<\/tr>\n
star\u6295\u5f71<\/td>\nGroup< * ><\/td>\n—<\/td>\nGroup<\u4efb\u4f55\u7c7b\u578b > \u90fd\u662f Group< * ><\/td>\n\u5b50\u7c7b\u7c7b\u578b\u53c2\u6570\u4e0d\u80fd\u505a\u65b9\u6cd5\u53c2\u6570\u4e5f\u4e0d\u80fd\u505a\u8fd4\u56de\u503c<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"excerpt":{"rendered":"
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