{"id":1093,"date":"2022-10-23T22:47:04","date_gmt":"2022-10-23T14:47:04","guid":{"rendered":"https:\/\/qaqaq.top\/?p=1093"},"modified":"2022-11-27T12:39:50","modified_gmt":"2022-11-27T04:39:50","slug":"%e5%b8%b8%e7%94%a8%e7%b1%bb-string%e7%9a%84%e5%b8%b8%e7%94%a8%e6%96%b9%e6%b3%951%e3%80%81string%e7%9a%84%e5%b8%b8%e7%94%a8%e6%96%b9%e6%b3%952%e3%80%81string%e7%9a%84%e5%b8%b8%e7%94%a8%e6%96%b9","status":"publish","type":"post","link":"https:\/\/qaqaq.top\/?p=1093","title":{"rendered":"\u5e38\u7528\u7c7b-String\u7684\u5e38\u7528\u65b9\u6cd51\u3001String\u7684\u5e38\u7528\u65b9\u6cd52\u3001String\u7684\u5e38\u7528\u65b9\u6cd53"},"content":{"rendered":"\n<pre class=\"wp-block-code\"><code>package top.qaqaq.java.P457;\r\n\r\nimport org.junit.jupiter.api.Test;\r\n\r\n\/**\r\n * @author RichieZhang\r\n * @create 2022-10-22 \u4e0b\u5348 3:58\r\n *\/\r\npublic class StringMethodTest {\r\n\r\n    \/*\r\n    \u66ff\u6362\uff1a\r\n    String replace(char oldChar, char newChar)\uff1a\u8fd4\u56de\u4e00\u4e2a\u65b0\u7684\u5b57\u7b26\u4e32\uff0c\u5b83\u662f\u901a\u8fc7\u7528 newChar \u66ff\u6362\u6b64\u5b57\u7b26\u4e32\u4e2d\u51fa\u73b0\u7684\u6240\u6709 oldChar \u5f97\u5230\u7684\u3002\r\n    String replace(CharSequence target, CharSequence replacement)\uff1a\u4f7f\u7528\u6307\u5b9a\u7684\u5b57\u9762\u503c\u66ff\u6362\u5e8f\u5217\u66ff\u6362\u6b64\u5b57\u7b26\u4e32\u6240\u6709\u5339\u914d\u5b57\u9762\u503c\u76ee\u6807\u5e8f\u5217\u7684\u5b50\u5b57\u7b26\u4e32\u3002\r\n    String replaceAll(String regex, String replacement) \uff1a \u4f7f \u7528 \u7ed9 \u5b9a \u7684replacement \u66ff\u6362\u6b64\u5b57\u7b26\u4e32\u6240\u6709\u5339\u914d\u7ed9\u5b9a\u7684\u6b63\u5219\u8868\u8fbe\u5f0f\u7684\u5b50\u5b57\u7b26\u4e32\u3002\r\n    String replaceFirst(String regex, String replacement) \uff1a \u4f7f \u7528 \u7ed9 \u5b9a \u7684replacement \u66ff\u6362\u6b64\u5b57\u7b26\u4e32\u5339\u914d\u7ed9\u5b9a\u7684\u6b63\u5219\u8868\u8fbe\u5f0f\u7684\u7b2c\u4e00\u4e2a\u5b50\u5b57\u7b26\u4e32\u3002\r\n    \u5339\u914d\uff1a\r\n    boolean matches(String regex)\uff1a\u544a\u77e5\u6b64\u5b57\u7b26\u4e32\u662f\u5426\u5339\u914d\u7ed9\u5b9a\u7684\u6b63\u5219\u8868\u8fbe\u5f0f\u3002\r\n    \u5207\u7247\uff1a\r\n    String&#91;] split(String regex)\uff1a\u6839\u636e\u7ed9\u5b9a\u6b63\u5219\u8868\u8fbe\u5f0f\u7684\u5339\u914d\u62c6\u5206\u6b64\u5b57\u7b26\u4e32\u3002\r\n    String&#91;] split(String regex, int limit)\uff1a\u6839\u636e\u5339\u914d\u7ed9\u5b9a\u7684\u6b63\u5219\u8868\u8fbe\u5f0f\u6765\u62c6\u5206\u6b64\u5b57\u7b26\u4e32\uff0c\u6700\u591a\u4e0d\u8d85\u8fc7limit\u4e2a\uff0c\u5982\u679c\u8d85\u8fc7\u4e86\uff0c\u5269\u4e0b\u7684\u5168\u90e8\u90fd\u653e\u5230\u6700\u540e\u4e00\u4e2a\u5143\u7d20\u4e2d\u3002\r\n     *\/\r\n\r\n    @Test\r\n    public void test4(){\r\n        String str1 = \"\u5317\u4eac\u5c1a\u7845\u8c37\u6559\u80b2\u5317\u4eac\";\r\n        String str2 = str1.replace('\u5317', '\u4e1c');\r\n\r\n        System.out.println(str1);\r\n        System.out.println(str2);\r\n\r\n        String str3 = str1.replace(\"\u5317\u4eac\", \"\u4e0a\u6d77\");\r\n\r\n        System.out.println(\"*******************************\");\r\n        String str = \"12hello34world5java7891mysql456\";\r\n        \/\/\u628a\u5b57\u7b26\u4e32\u4e2d\u7684\u6570\u5b57\u66ff\u6362\u6210,\uff0c\u5982\u679c\u7ed3\u679c\u4e2d\u5f00\u5934\u548c\u7ed3\u5c3e\u6709\uff0c\u7684\u8bdd\u53bb\u6389\r\n        String string = str.replaceAll(\"\\\\d+\", \",\").replaceAll(\"^,|,$\", \"\");\r\n        System.out.println(string);\r\n\r\n        System.out.println(\"*******************************\");\r\n        str = \"12345\";\r\n        \/\/\u5224\u65adstr\u5b57\u7b26\u4e32\u4e2d\u662f\u5426\u5168\u90e8\u6709\u6570\u5b57\u7ec4\u6210\uff0c\u5373\u67091-n\u4e2a\u6570\u5b57\u7ec4\u6210\r\n        boolean matches = str.matches(\"\\\\d+\");\r\n        System.out.println(matches);\r\n        String tel = \"0571-453428999\";\r\n        \/\/\u5224\u65ad\u8fd9\u662f\u5426\u662f\u4e00\u4e2a\u676d\u5dde\u7684\u56fa\u5b9a\u7535\u8bdd\r\n        boolean result = tel.matches(\"0571-\\\\d{7,8}\");\r\n        System.out.println(result);\r\n\r\n        System.out.println(\"*******************************\");\r\n        str = \"hello|world|java\";\r\n        String&#91;] strs = str.split(\"\\\\|\");\r\n        for (int i = 0; i &lt; strs.length; i++) {\r\n            System.out.println(strs&#91;i]);\r\n        }\r\n        System.out.println();\r\n        str2 = \"hello.world.java\";\r\n        String&#91;] strs2 = str2.split(\"\\\\.\");\r\n        for (int i = 0; i &lt; strs2.length; i++) {\r\n            System.out.println(strs2&#91;i]);\r\n        }\r\n    }\r\n\r\n    \/*\r\n    boolean endsWith(String suffix)\uff1a\u6d4b\u8bd5\u6b64\u5b57\u7b26\u4e32\u662f\u5426\u4ee5\u6307\u5b9a\u7684\u540e\u7f00\u7ed3\u675f\r\n    boolean startsWith(String prefix)\uff1a\u6d4b\u8bd5\u6b64\u5b57\u7b26\u4e32\u662f\u5426\u4ee5\u6307\u5b9a\u7684\u524d\u7f00\u5f00\u59cb\r\n    boolean startsWith(String prefix, int toffset)\uff1a\u6d4b\u8bd5\u6b64\u5b57\u7b26\u4e32\u4ece\u6307\u5b9a\u7d22\u5f15\u5f00\u59cb\u7684\u5b50\u5b57\u7b26\u4e32\u662f\u5426\u4ee5\u6307\u5b9a\u524d\u7f00\u5f00\u59cb\r\n\r\n    boolean contains(CharSequence s)\uff1a\u5f53\u4e14\u4ec5\u5f53\u6b64\u5b57\u7b26\u4e32\u5305\u542b\u6307\u5b9a\u7684 char \u503c\u5e8f\u5217\u65f6\uff0c\u8fd4\u56de true\r\n    int indexOf(String str)\uff1a\u8fd4\u56de\u6307\u5b9a\u5b50\u5b57\u7b26\u4e32\u5728\u6b64\u5b57\u7b26\u4e32\u4e2d\u7b2c\u4e00\u6b21\u51fa\u73b0\u5904\u7684\u7d22\u5f15\r\n    int indexOf(String str, int fromIndex)\uff1a\u8fd4\u56de\u6307\u5b9a\u5b50\u5b57\u7b26\u4e32\u5728\u6b64\u5b57\u7b26\u4e32\u4e2d\u7b2c\u4e00\u6b21\u51fa\u73b0\u5904\u7684\u7d22\u5f15\uff0c\u4ece\u6307\u5b9a\u7684\u7d22\u5f15\u5f00\u59cb\r\n    int lastIndexOf(String str)\uff1a\u8fd4\u56de\u6307\u5b9a\u5b50\u5b57\u7b26\u4e32\u5728\u6b64\u5b57\u7b26\u4e32\u4e2d\u6700\u53f3\u8fb9\u51fa\u73b0\u5904\u7684\u7d22\u5f15\r\n    int lastIndexOf(String str, int fromIndex)\uff1a\u8fd4\u56de\u6307\u5b9a\u5b50\u5b57\u7b26\u4e32\u5728\u6b64\u5b57\u7b26\u4e32\u4e2d\u6700\u540e\u4e00\u6b21\u51fa\u73b0\u5904\u7684\u7d22\u5f15\uff0c\u4ece\u6307\u5b9a\u7684\u7d22\u5f15\u5f00\u59cb\u53cd\u5411\u641c\u7d22\r\n    \u6ce8\uff1aindexOf\u548clastIndexOf\u65b9\u6cd5\u5982\u679c\u672a\u627e\u5230\u90fd\u662f\u8fd4\u56de-1\r\n     *\/\r\n\r\n    @Test\r\n    public void test3() {\r\n        String str1 = \"hellowworld\";\r\n        boolean b1 = str1.endsWith(\"rld\");\r\n        System.out.println(b1);\r\n\r\n        boolean b2 = str1.startsWith(\"He\");\r\n        System.out.println(b2);\r\n\r\n        boolean b3 = str1.startsWith(\"ll\", 2);\r\n        System.out.println(b3);\r\n\r\n        String str2 = \"wor\";\r\n        System.out.println(str1.contains(str2));\r\n\r\n        System.out.println(str1.indexOf(\"lol\"));\r\n\r\n        System.out.println(str1.indexOf(\"lo\", 5));\r\n\r\n        String str3 = \"hellorworld\";\r\n\r\n        System.out.println(str3.lastIndexOf(\"or\"));\r\n        System.out.println(str3.lastIndexOf(\"or\", 6));\r\n\r\n        \/\/\u4ec0\u4e48\u60c5\u51b5\u4e0b\uff0cindexOf(str)\u548cLastIndexOf(str)\u8fd4\u56de\u503c\u76f8\u540c\uff1f\r\n        \/\/\u60c5\u51b5\u4e00\uff1a\u5b58\u5728\u552f\u4e00\u7684\u4e00\u4e2astr\u3002\u60c5\u51b5\u4e8c\uff1a\u4e0d\u5b58\u5728str\r\n    }\r\n\r\n    \/*\r\n    int length()\uff1a\u8fd4\u56de\u5b57\u7b26\u4e32\u7684\u957f\u5ea6\uff1a return value.length\r\n    char charAt(int index)\uff1a \u8fd4\u56de\u67d0\u7d22\u5f15\u5904\u7684\u5b57\u7b26return value&#91;index]\r\n    boolean isEmpty()\uff1a\u5224\u65ad\u662f\u5426\u662f\u7a7a\u5b57\u7b26\u4e32\uff1areturn value.length == 0\r\n    String toLowerCase()\uff1a\u4f7f\u7528\u9ed8\u8ba4\u8bed\u8a00\u73af\u5883\uff0c\u5c06 String \u4e2d\u7684\u6240\u6709\u5b57\u7b26\u8f6c\u6362\u4e3a\u5c0f\u5199\r\n    String toUpperCase()\uff1a\u4f7f\u7528\u9ed8\u8ba4\u8bed\u8a00\u73af\u5883\uff0c\u5c06 String \u4e2d\u7684\u6240\u6709\u5b57\u7b26\u8f6c\u6362\u4e3a\u5927\u5199\r\n    String trim()\uff1a\u8fd4\u56de\u5b57\u7b26\u4e32\u7684\u526f\u672c\uff0c\u5ffd\u7565\u524d\u5bfc\u7a7a\u767d\u548c\u5c3e\u90e8\u7a7a\u767d\r\n    boolean equals(Object obj)\uff1a\u6bd4\u8f83\u5b57\u7b26\u4e32\u7684\u5185\u5bb9\u662f\u5426\u76f8\u540c\r\n    boolean equalsIgnoreCase(String anotherString)\uff1a\u4e0eequals\u65b9\u6cd5\u7c7b\u4f3c\uff0c\u5ffd\u7565\u5927\u5c0f\u5199\r\n    String concat(String str)\uff1a\u5c06\u6307\u5b9a\u5b57\u7b26\u4e32\u8fde\u63a5\u5230\u6b64\u5b57\u7b26\u4e32\u7684\u7ed3\u5c3e\u3002 \u7b49\u4ef7\u4e8e\u7528\u201c+\u201d\r\n    int compareTo(String anotherString)\uff1a\u6bd4\u8f83\u4e24\u4e2a\u5b57\u7b26\u4e32\u7684\u5927\u5c0f\r\n    String substring(int beginIndex)\uff1a\u8fd4\u56de\u4e00\u4e2a\u65b0\u7684\u5b57\u7b26\u4e32\uff0c\u5b83\u662f\u6b64\u5b57\u7b26\u4e32\u7684\u4ecebeginIndex\u5f00\u59cb\u622a\u53d6\u5230\u6700\u540e\u7684\u4e00\u4e2a\u5b50\u5b57\u7b26\u4e32\u3002\r\n    String substring(int beginIndex, int endIndex) \uff1a\u8fd4\u56de\u4e00\u4e2a\u65b0\u5b57\u7b26\u4e32\uff0c\u5b83\u662f\u6b64\u5b57\u7b26\u4e32\u4ecebeginIndex\u5f00\u59cb\u622a\u53d6\u5230endIndex(\u4e0d\u5305\u542b)\u7684\u4e00\u4e2a\u5b50\u5b57\u7b26\u4e32\u3002\r\n     *\/\r\n\r\n    @Test\r\n    public void test2() {\r\n        String s1 = \"HelloWorld\";\r\n        String s2 = \"helloworld\";\r\n        System.out.println(s1.equals(s2));\r\n        System.out.println(s1.equalsIgnoreCase(s2));\r\n\r\n        String s3 = \"abc\";\r\n        String s4 = s3.concat(\"def\");\r\n        System.out.println(s4);\r\n\r\n        String s5 = \"abc\";\r\n        String s6 = new String(\"abe\");\r\n        System.out.println(s5.compareTo(s6));\/\/ \u6d89\u53ca\u5230\u5b57\u7b26\u4e32\u6392\u5e8f\r\n\r\n        String s7 = \"\u5317\u4eac\u5c1a\u7845\u8c37\u6559\u80b2\";\r\n        String s8 = s7.substring(2);\r\n        System.out.println(s7);\r\n        System.out.println(s8);\r\n\r\n        String s9 = s7.substring(2, 5);\r\n        System.out.println(s9);\r\n    }\r\n\r\n    @Test\r\n    public void test1() {\r\n        String s1 = \"HelloWorld\";\r\n        System.out.println(s1.length());\r\n        System.out.println(s1.charAt(0));\r\n        System.out.println(s1.charAt(9));\r\n\/\/        System.out.println(s1.charAt(10));\r\n\r\n\/\/        s1 = \"\";\r\n        System.out.println(s1.isEmpty());\r\n\r\n        String s2 = s1.toLowerCase();\r\n        System.out.println(s1);\/\/s1\u4e0d\u53ef\u53d8\u7684\uff0c\u4ecd\u7136\u4e3a\u539f\u6765\u7684\u5b57\u7b26\u4e32\r\n        System.out.println(s2);\/\/\u6539\u6210\u5c0f\u5199\u4ee5\u540e\u7684\u5b57\u7b26\u4e32\r\n\r\n        String s3 = \"    he  llo    world    \";\r\n        String s4 = s3.trim();\r\n        System.out.println(\"-----\" + s3 + \"-----\");\r\n        System.out.println(\"-----\" + s4 + \"-----\");\r\n    }\r\n\r\n\r\n}\r\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[46],"class_list":["post-1093","post","type-post","status-publish","format-standard","hentry","category-java-code","tag-java"],"_links":{"self":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/1093"}],"collection":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1093"}],"version-history":[{"count":1,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/1093\/revisions"}],"predecessor-version":[{"id":1094,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/1093\/revisions\/1094"}],"wp:attachment":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1093"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1093"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1093"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}