{"id":2206,"date":"2025-03-02T10:27:53","date_gmt":"2025-03-02T02:27:53","guid":{"rendered":"https:\/\/www.laixuexila.com\/?p=2206"},"modified":"2025-03-02T10:27:53","modified_gmt":"2025-03-02T02:27:53","slug":"java-string-%e7%b1%bb","status":"publish","type":"post","link":"https:\/\/www.laixuexila.com\/index.php\/2025\/03\/02\/java-string-%e7%b1%bb\/","title":{"rendered":"Java String \u7c7b"},"content":{"rendered":"\n

String<\/code> \u7c7b\u662f Java \u4e2d\u6700\u5e38\u7528\u7684\u7c7b\u4e4b\u4e00\uff0c\u7528\u4e8e\u8868\u793a\u548c\u64cd\u4f5c\u5b57\u7b26\u4e32\u3002\u4e0e\u5176\u4ed6\u7c7b\u4e0d\u540c\uff0cString<\/code> \u662f\u4e0d\u53ef\u53d8\u7684\uff08immutable\uff09\uff0c\u5373\u4e00\u65e6\u521b\u5efa\u4e86 String<\/code> \u5bf9\u8c61\uff0c\u5b83\u7684\u5185\u5bb9\u5c31\u4e0d\u80fd\u66f4\u6539\u3002String<\/code> \u7c7b\u4f4d\u4e8e java.lang<\/code> \u5305\u4e0b\u3002<\/p>\n\n\n\n

1. String<\/code> \u7c7b\u6982\u8ff0<\/strong><\/h3>\n\n\n\n
    \n
  • String<\/code> \u7c7b\u7528\u4e8e\u8868\u793a\u4e00\u7cfb\u5217\u5b57\u7b26\u3002<\/li>\n\n\n\n
  • \u5b57\u7b26\u4e32\u5728 Java \u4e2d\u662f\u5bf9\u8c61\uff0c\u4f46\u5b83\u4eec\u6709\u4e00\u4e9b\u7279\u6b8a\u7684\u5904\u7406\u65b9\u5f0f\u3002<\/li>\n\n\n\n
  • String<\/code> \u662f\u4e0d\u53ef\u53d8\u7684\uff0c\u8fd9\u610f\u5473\u7740\u4efb\u4f55\u5bf9\u5b57\u7b26\u4e32\u7684\u4fee\u6539\u90fd\u4f1a\u751f\u6210\u4e00\u4e2a\u65b0\u7684\u5b57\u7b26\u4e32\uff0c\u800c\u4e0d\u4f1a\u6539\u53d8\u539f\u6765\u7684\u5b57\u7b26\u4e32\u3002<\/li>\n\n\n\n
  • \u5b57\u7b26\u4e32\u4f7f\u7528 UTF-16 \u7f16\u7801\u5b58\u50a8\u3002<\/li>\n<\/ul>\n\n\n\n

    2. \u5e38\u7528\u7684 String<\/code> \u7c7b\u65b9\u6cd5<\/strong><\/h3>\n\n\n\n

    2.1 \u521b\u5efa\u5b57\u7b26\u4e32<\/h4>\n\n\n\n
      \n
    • \u4f7f\u7528\u5b57\u9762\u91cf<\/strong>\uff1a<\/li>\n<\/ul>\n\n\n\n
        String str = \"Hello\";<\/code><\/pre>\n\n\n\n
        \n
      • \u4f7f\u7528 new<\/code> \u5173\u952e\u5b57<\/strong>\uff1a<\/li>\n<\/ul>\n\n\n\n
          String str = new String(\"Hello\");<\/code><\/pre>\n\n\n\n
        2.2 \u83b7\u53d6\u5b57\u7b26\u4e32\u7684\u957f\u5ea6<\/h4>\n\n\n\n
          \n
        • length()<\/code> \u65b9\u6cd5\u8fd4\u56de\u5b57\u7b26\u4e32\u7684\u957f\u5ea6\uff08\u5b57\u7b26\u6570\uff09\u3002<\/li>\n<\/ul>\n\n\n\n
          String str = \"Hello\";\nSystem.out.println(str.length());  \/\/ \u8f93\u51fa 5<\/code><\/pre>\n\n\n\n
          2.3 \u5b57\u7b26\u4e32\u62fc\u63a5<\/h4>\n\n\n\n
            \n
          • \u4f7f\u7528 +<\/code> \u8fd0\u7b97\u7b26\uff1a<\/li>\n<\/ul>\n\n\n\n
              String str1 = \"Hello\";\n  String str2 = \" World!\";\n  String result = str1 + str2;\n  System.out.println(result);  \/\/ \u8f93\u51fa \"Hello World!\"<\/code><\/pre>\n\n\n\n
              \n
            • \u4f7f\u7528 concat()<\/code> \u65b9\u6cd5\uff1a<\/li>\n<\/ul>\n\n\n\n
                String result = str1.concat(str2);\n  System.out.println(result);  \/\/ \u8f93\u51fa \"Hello World!\"<\/code><\/pre>\n\n\n\n
              2.4 \u5b57\u7b26\u4e32\u6bd4\u8f83<\/h4>\n\n\n\n
                \n
              • equals()<\/code><\/strong>\uff1a\u6bd4\u8f83\u4e24\u4e2a\u5b57\u7b26\u4e32\u7684\u5185\u5bb9\u662f\u5426\u76f8\u540c\uff08\u533a\u5206\u5927\u5c0f\u5199\uff09\u3002<\/li>\n<\/ul>\n\n\n\n
                  String str1 = \"Hello\";\n  String str2 = \"hello\";\n  System.out.println(str1.equals(str2));  \/\/ \u8f93\u51fa false<\/code><\/pre>\n\n\n\n
                  \n
                • equalsIgnoreCase()<\/code><\/strong>\uff1a\u6bd4\u8f83\u4e24\u4e2a\u5b57\u7b26\u4e32\u7684\u5185\u5bb9\u662f\u5426\u76f8\u540c\uff08\u5ffd\u7565\u5927\u5c0f\u5199\uff09\u3002<\/li>\n<\/ul>\n\n\n\n
                    System.out.println(str1.equalsIgnoreCase(str2));  \/\/ \u8f93\u51fa true<\/code><\/pre>\n\n\n\n
                    \n
                  • compareTo()<\/code><\/strong>\uff1a\u6309\u5b57\u5178\u987a\u5e8f\u6bd4\u8f83\u4e24\u4e2a\u5b57\u7b26\u4e32\u3002\u5982\u679c\u5f53\u524d\u5b57\u7b26\u4e32\u5c0f\u4e8e\u76ee\u6807\u5b57\u7b26\u4e32\uff0c\u8fd4\u56de\u8d1f\u6570\uff1b\u7b49\u4e8e\u8fd4\u56de 0\uff1b\u5927\u4e8e\u8fd4\u56de\u6b63\u6570\u3002<\/li>\n<\/ul>\n\n\n\n
                      String str1 = \"abc\";\n  String str2 = \"xyz\";\n  System.out.println(str1.compareTo(str2));  \/\/ \u8f93\u51fa\u8d1f\u6570\uff0c\u56e0\u4e3a \"abc\" \u5c0f\u4e8e \"xyz\"<\/code><\/pre>\n\n\n\n
                    2.5 \u5b57\u7b26\u4e32\u67e5\u627e<\/h4>\n\n\n\n
                      \n
                    • indexOf()<\/code><\/strong>\uff1a\u67e5\u627e\u5b50\u5b57\u7b26\u4e32\u6216\u5b57\u7b26\u7b2c\u4e00\u6b21\u51fa\u73b0\u7684\u4f4d\u7f6e\u3002<\/li>\n<\/ul>\n\n\n\n
                        String str = \"Hello World\";\n  System.out.println(str.indexOf('o'));  \/\/ \u8f93\u51fa 4\n  System.out.println(str.indexOf(\"World\"));  \/\/ \u8f93\u51fa 6<\/code><\/pre>\n\n\n\n
                        \n
                      • lastIndexOf()<\/code><\/strong>\uff1a\u67e5\u627e\u5b50\u5b57\u7b26\u4e32\u6216\u5b57\u7b26\u6700\u540e\u4e00\u6b21\u51fa\u73b0\u7684\u4f4d\u7f6e\u3002<\/li>\n<\/ul>\n\n\n\n
                          System.out.println(str.lastIndexOf('o'));  \/\/ \u8f93\u51fa 7<\/code><\/pre>\n\n\n\n
                        2.6 \u622a\u53d6\u5b57\u7b26\u4e32<\/h4>\n\n\n\n
                          \n
                        • substring()<\/code><\/strong>\uff1a\u4ece\u6307\u5b9a\u4f4d\u7f6e\u5f00\u59cb\u622a\u53d6\u5b57\u7b26\u4e32\u3002<\/li>\n<\/ul>\n\n\n\n
                            String str = \"Hello World\";\n  String substr = str.substring(6);\n  System.out.println(substr);  \/\/ \u8f93\u51fa \"World\"\n\n  String substr2 = str.substring(0, 5);\n  System.out.println(substr2);  \/\/ \u8f93\u51fa \"Hello\"<\/code><\/pre>\n\n\n\n
                          2.7 \u5b57\u7b26\u4e32\u66ff\u6362<\/h4>\n\n\n\n
                            \n
                          • replace()<\/code><\/strong>\uff1a\u66ff\u6362\u6307\u5b9a\u7684\u5b57\u7b26\u6216\u5b50\u5b57\u7b26\u4e32\u3002<\/li>\n<\/ul>\n\n\n\n
                              String str = \"Hello World\";\n  String result = str.replace(\"World\", \"Java\");\n  System.out.println(result);  \/\/ \u8f93\u51fa \"Hello Java\"<\/code><\/pre>\n\n\n\n
                            2.8 \u5b57\u7b26\u4e32\u53bb\u9664\u7a7a\u767d\u5b57\u7b26<\/h4>\n\n\n\n
                              \n
                            • trim()<\/code><\/strong>\uff1a\u53bb\u9664\u5b57\u7b26\u4e32\u524d\u540e\u7684\u7a7a\u767d\u5b57\u7b26\uff08\u5982\u7a7a\u683c\u3001\u6362\u884c\u7b49\uff09\u3002<\/li>\n<\/ul>\n\n\n\n
                                String str = \"  Hello World  \";\n  System.out.println(str.trim());  \/\/ \u8f93\u51fa \"Hello World\"<\/code><\/pre>\n\n\n\n
                              2.9 \u8f6c\u6362\u5b57\u7b26\u4e32\u5927\u5c0f\u5199<\/h4>\n\n\n\n
                                \n
                              • toLowerCase()<\/code><\/strong>\uff1a\u5c06\u5b57\u7b26\u4e32\u8f6c\u6362\u4e3a\u5c0f\u5199\u5b57\u6bcd\u3002<\/li>\n<\/ul>\n\n\n\n
                                  String str = \"HELLO\";\n  System.out.println(str.toLowerCase());  \/\/ \u8f93\u51fa \"hello\"<\/code><\/pre>\n\n\n\n
                                  \n
                                • toUpperCase()<\/code><\/strong>\uff1a\u5c06\u5b57\u7b26\u4e32\u8f6c\u6362\u4e3a\u5927\u5199\u5b57\u6bcd\u3002<\/li>\n<\/ul>\n\n\n\n
                                    String str = \"hello\";\n  System.out.println(str.toUpperCase());  \/\/ \u8f93\u51fa \"HELLO\"<\/code><\/pre>\n\n\n\n
                                  2.10 \u5b57\u7b26\u4e32\u8fde\u63a5\uff08StringBuilder\/StringBuffer\uff09<\/h4>\n\n\n\n
                                  \u7531\u4e8e\u5b57\u7b26\u4e32\u662f\u4e0d\u53ef\u53d8\u7684\uff0c\u6bcf\u6b21\u62fc\u63a5\u5b57\u7b26\u4e32\u90fd\u4f1a\u521b\u5efa\u65b0\u7684\u5bf9\u8c61\uff0c\u8fd9\u4f1a\u5bfc\u81f4\u6027\u80fd\u5f00\u9500\u3002\u5982\u679c\u9700\u8981\u9891\u7e41\u62fc\u63a5\u5b57\u7b26\u4e32\uff0c\u53ef\u4ee5\u4f7f\u7528 StringBuilder<\/code> \u6216 StringBuffer<\/code> \u7c7b\u3002<\/p>\n\n\n\n
                                    \n
                                  • StringBuilder<\/code> \u548c StringBuffer<\/code><\/strong>\uff1a\u8fd9\u4e24\u4e2a\u7c7b\u63d0\u4f9b\u4e86\u53ef\u53d8\u7684\u5b57\u7b26\u4e32\uff0c\u53ef\u4ee5\u9ad8\u6548\u5730\u8fdb\u884c\u62fc\u63a5\u64cd\u4f5c\u3002<\/li>\n<\/ul>\n\n\n\n
                                      StringBuilder sb = new StringBuilder(\"Hello\");\n  sb.append(\" World\");\n  System.out.println(sb.toString());  \/\/ \u8f93\u51fa \"Hello World\"<\/code><\/pre>\n\n\n\n
                                    2.11 \u8f6c\u6362\u4e3a\u5b57\u7b26\u6570\u7ec4<\/h4>\n\n\n\n
                                      \n
                                    • toCharArray()<\/code><\/strong>\uff1a\u5c06\u5b57\u7b26\u4e32\u8f6c\u6362\u4e3a\u5b57\u7b26\u6570\u7ec4\u3002<\/li>\n<\/ul>\n\n\n\n
                                        String str = \"Hello\";\n  char[] charArray = str.toCharArray();\n  System.out.println(charArray);  \/\/ \u8f93\u51fa \"Hello\"<\/code><\/pre>\n\n\n\n
                                      2.12 \u5b57\u7b26\u4e32\u7684\u5206\u5272<\/h4>\n\n\n\n
                                        \n
                                      • split()<\/code><\/strong>\uff1a\u6839\u636e\u6307\u5b9a\u7684\u5206\u9694\u7b26\u5c06\u5b57\u7b26\u4e32\u5206\u5272\u6210\u591a\u4e2a\u90e8\u5206\uff0c\u8fd4\u56de\u4e00\u4e2a\u5b57\u7b26\u4e32\u6570\u7ec4\u3002<\/li>\n<\/ul>\n\n\n\n
                                          String str = \"apple,banana,orange\";\n  String[] fruits = str.split(\",\");\n  for (String fruit : fruits) {\n      System.out.println(fruit);\n  }\n  \/\/ \u8f93\u51fa\uff1a\n  \/\/ apple\n  \/\/ banana\n  \/\/ orange<\/code><\/pre>\n\n\n\n
                                        3. String<\/code> \u7c7b\u7684\u5e38\u89c1\u5b9e\u4f8b<\/strong><\/h3>\n\n\n\n
                                        3.1 \u5b57\u7b26\u4e32\u62fc\u63a5<\/h4>\n\n\n\n
                                        public class StringExample {\n    public static void main(String[] args) {\n        String str1 = \"Java\";\n        String str2 = \" is awesome!\";\n\n        \/\/ \u4f7f\u7528 + \u8fd0\u7b97\u7b26\n        String result1 = str1 + str2;\n        System.out.println(result1);  \/\/ \u8f93\u51fa \"Java is awesome!\"\n\n        \/\/ \u4f7f\u7528 concat() \u65b9\u6cd5\n        String result2 = str1.concat(str2);\n        System.out.println(result2);  \/\/ \u8f93\u51fa \"Java is awesome!\"\n    }\n}<\/code><\/pre>\n\n\n\n
                                        3.2 \u5b57\u7b26\u4e32\u6bd4\u8f83<\/h4>\n\n\n\n
                                        public class StringComparisonExample {\n    public static void main(String[] args) {\n        String str1 = \"Hello\";\n        String str2 = \"hello\";\n\n        \/\/ \u4f7f\u7528 equals() \u6bd4\u8f83\n        System.out.println(str1.equals(str2));  \/\/ \u8f93\u51fa false\n\n        \/\/ \u4f7f\u7528 equalsIgnoreCase() \u6bd4\u8f83\n        System.out.println(str1.equalsIgnoreCase(str2));  \/\/ \u8f93\u51fa true\n    }\n}<\/code><\/pre>\n\n\n\n
                                        3.3 \u5b57\u7b26\u4e32\u622a\u53d6<\/h4>\n\n\n\n
                                        public class StringSubstringExample {\n    public static void main(String[] args) {\n        String str = \"Hello World\";\n\n        \/\/ \u622a\u53d6\u4ece\u4f4d\u7f6e 6 \u5230\u7ed3\u5c3e\u7684\u90e8\u5206\n        String substr = str.substring(6);\n        System.out.println(substr);  \/\/ \u8f93\u51fa \"World\"\n\n        \/\/ \u622a\u53d6\u4ece\u4f4d\u7f6e 0 \u5230\u4f4d\u7f6e 5 \u7684\u90e8\u5206\n        String substr2 = str.substring(0, 5);\n        System.out.println(substr2);  \/\/ \u8f93\u51fa \"Hello\"\n    }\n}<\/code><\/pre>\n\n\n\n
                                        3.4 \u5b57\u7b26\u4e32\u66ff\u6362<\/h4>\n\n\n\n
                                        public class StringReplaceExample {\n    public static void main(String[] args) {\n        String str = \"Hello World!\";\n        \/\/ \u66ff\u6362 \"World\" \u4e3a \"Java\"\n        String result = str.replace(\"World\", \"Java\");\n        System.out.println(result);  \/\/ \u8f93\u51fa \"Hello Java!\"\n    }\n}<\/code><\/pre>\n\n\n\n
                                        3.5 \u5b57\u7b26\u4e32\u5206\u5272<\/h4>\n\n\n\n
                                        public class StringSplitExample {\n    public static void main(String[] args) {\n        String str = \"apple,banana,orange\";\n        String[] fruits = str.split(\",\");\n\n        for (String fruit : fruits) {\n            System.out.println(fruit);\n        }\n    }\n}<\/code><\/pre>\n\n\n\n
                                        4. \u603b\u7ed3<\/strong><\/h3>\n\n\n\n
                                          \n
                                        • \u4e0d\u53ef\u53d8\u6027<\/strong>\uff1aString<\/code> \u5bf9\u8c61\u4e00\u65e6\u521b\u5efa\u540e\u4e0d\u53ef\u66f4\u6539\uff0c\u6bcf\u6b21\u5bf9\u5b57\u7b26\u4e32\u7684\u64cd\u4f5c\u90fd\u4f1a\u8fd4\u56de\u4e00\u4e2a\u65b0\u7684\u5b57\u7b26\u4e32\u3002<\/li>\n\n\n\n
                                        • \u5e38\u7528\u65b9\u6cd5<\/strong>\uff1alength()<\/code>\u3001equals()<\/code>\u3001substring()<\/code>\u3001indexOf()<\/code>\u3001replace()<\/code> \u7b49\u90fd\u662f\u64cd\u4f5c\u5b57\u7b26\u4e32\u7684\u5e38\u7528\u65b9\u6cd5\u3002<\/li>\n\n\n\n
                                        • \u6027\u80fd\u4f18\u5316<\/strong>\uff1a\u9891\u7e41\u62fc\u63a5\u5b57\u7b26\u4e32\u65f6\uff0c\u5efa\u8bae\u4f7f\u7528 StringBuilder<\/code> \u6216 StringBuffer<\/code>\uff0c\u56e0\u4e3a\u5b83\u4eec\u662f\u53ef\u53d8\u7684\uff0c\u80fd\u591f\u63d0\u9ad8\u6027\u80fd\u3002<\/li>\n<\/ul>\n\n\n\n
                                          \u66f4\u591a\u8be6\u7ec6\u5185\u5bb9\u8bf7\u5173\u6ce8\u5176\u4ed6\u76f8\u5173\u6587\u7ae0\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"
                                          String \u7c7b\u662f Java \u4e2d\u6700\u5e38\u7528\u7684\u7c7b\u4e4b\u4e00\uff0c\u7528\u4e8e\u8868\u793a\u548c\u64cd\u4f5c\u5b57\u7b26\u4e32\u3002\u4e0e\u5176\u4ed6\u7c7b\u4e0d\u540c\uff0cString \u662f\u4e0d\u53ef\u53d8\u7684\uff08 […]<\/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-2206","post","type-post","status-publish","format-standard","hentry","category-java"],"_links":{"self":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/2206","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=2206"}],"version-history":[{"count":1,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/2206\/revisions"}],"predecessor-version":[{"id":2207,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/2206\/revisions\/2207"}],"wp:attachment":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media?parent=2206"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/categories?post=2206"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/tags?post=2206"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}