{"id":116,"date":"2016-06-23T14:59:24","date_gmt":"2016-06-23T06:59:24","guid":{"rendered":"http:\/\/jason19659.pw\/?p=116"},"modified":"2016-06-27T09:54:33","modified_gmt":"2016-06-27T01:54:33","slug":"%e5%85%b3%e4%ba%8ejava-string%e7%9a%84%e5%92%8cstringbuilder","status":"publish","type":"post","link":"https:\/\/t2t2.cc\/?p=116","title":{"rendered":"\u5173\u4e8ejava String\u7684+=\u548cStringBuilder"},"content":{"rendered":"<p>\u4ee5\u524d\u4e00\u76f4\u4ee5\u4e3a\u8fd9\u79cd\u5199\u6cd5<\/p>\n<pre class=\"brush: java; title: ; notranslate\" title=\"\">\r\nString test = &quot;123&quot;\uff0b&quot;345&quot;+&quot;456&quot;;\r\n\r\n<\/pre>\n<p>\u4ee5\u524d\u8ba4\u4e3aString \uff0b \u6548\u7387\u662f\u7279\u522b\u4f4e\u7684\uff0c\u6bcf\u6b21\u90fd\u4f1a\u521b\u5efa\u4e00\u4e2a\u65b0\u7684\u5b57\u7b26\u4e32\uff0c\u5e94\u8be5\u7528StringBuilder.append\u4ee3\u66ff\u3002\u6700\u8fd1\u5076\u7136\u770b\u4e86\u4e0bjdk api\u6587\u6863<\/p>\n<p><em>The Java language provides special support for the string concatenation operator ( + ), and for conversion of other objects to strings. String concatenation is implemented through the StringBuilder(or StringBuffer) class and its append method. String conversions are implemented through the method toString, defined by Object and inherited by all classes in Java. For additional information on string concatenation and conversion, see Gosling, Joy, and Steele, The Java Language Specification.<\/em><\/p>\n<p><em><br \/>\nJava \u8bed\u8a00\u63d0\u4f9b\u5bf9\u5b57\u7b26\u4e32\u4e32\u8054\u7b26\u53f7\uff08&#8221;+&#8221;\uff09\u4ee5\u53ca\u5c06\u5176\u4ed6\u5bf9\u8c61\u8f6c\u6362\u4e3a\u5b57\u7b26\u4e32\u7684\u7279\u6b8a\u652f\u6301\u3002\u5b57\u7b26\u4e32\u4e32\u8054\u662f\u901a\u8fc7 <code>StringBuilder<\/code>\uff08\u6216 <code>StringBuffer<\/code>\uff09\u7c7b\u53ca\u5176<code>append<\/code> \u65b9\u6cd5\u5b9e\u73b0\u7684\u3002\u5b57\u7b26\u4e32\u8f6c\u6362\u662f\u901a\u8fc7 <code>toString<\/code> \u65b9\u6cd5\u5b9e\u73b0\u7684\uff0c\u8be5\u65b9\u6cd5\u7531 <code>Object<\/code> \u7c7b\u5b9a\u4e49\uff0c\u5e76\u53ef\u88ab Java \u4e2d\u7684\u6240\u6709\u7c7b\u7ee7\u627f\u3002\u6709\u5173\u5b57\u7b26\u4e32\u4e32\u8054\u548c\u8f6c\u6362\u7684\u66f4\u591a\u4fe1\u606f\uff0c\u8bf7\u53c2\u9605 Gosling\u3001Joy \u548c Steele \u5408\u8457\u7684 <i>The Java Language Specification<\/i>\u3002<br \/>\n<\/em><br \/>\n\u7136\u800c\u6211\u770b\u4e86\u4e00\u4e0b<code>StringBuilder<\/code>\u7684<code>toString<\/code>\u65b9\u6cd5<\/p>\n<pre class=\"brush: java; title: ; notranslate\" title=\"\">\r\n    @Override\r\n    public String toString() {\r\n        \/\/ Create a copy, don't share the array\r\n        return new String(value, 0, count);\r\n    }\r\n<\/pre>\n<p>\u8fd8\u662f\u4f1a\u6bcf\u6b21\u521b\u5efa\u4e00\u4e2a\u65b0\u7684\u5b57\u7b26\u4e32\uff0c\u6240\u4ee5\u5982\u679c\u8fd9\u6837\u5199<\/p>\n<pre class=\"brush: java; title: ; notranslate\" title=\"\">\r\n                String test = &quot;&quot;;\r\n\t\tfor (Integer i : treeSet) {\r\n\t\t\ttest += i;\r\n\t\t}\r\n<\/pre>\n<p>\u8fd8\u662f\u7b49\u4e8e<\/p>\n<pre class=\"brush: java; title: ; notranslate\" title=\"\">\r\n                String test = &quot;&quot;;\r\n\t\tfor (Integer i : treeSet) {\r\n\t\t\ttest \uff1d stringBuilder.append(i).toString();\r\n\t\t}\r\n<\/pre>\n<p>\u8fd8\u662f\u4f1a\u6bcf\u6b21\u521b\u5efa\u4e00\u4e2a\u65b0\u7684\u5bf9\u8c61\u3002<br \/>\n\u6240\u4ee5\u8bf4\u7136\u5e76\u5375\uff0c\u8fd8\u662f\u7528+\u6ca1\u95ee\u9898\u4e0d\u8981\u7528+=&#8230;..<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4ee5\u524d\u4e00\u76f4\u4ee5\u4e3a\u8fd9\u79cd\u5199\u6cd5 String test = &quot;123&quot;\uff0b&quot;345&#038;quot&hellip; <a href=\"https:\/\/t2t2.cc\/?p=116\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/t2t2.cc\/index.php?rest_route=\/wp\/v2\/posts\/116"}],"collection":[{"href":"https:\/\/t2t2.cc\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/t2t2.cc\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/t2t2.cc\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/t2t2.cc\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=116"}],"version-history":[{"count":3,"href":"https:\/\/t2t2.cc\/index.php?rest_route=\/wp\/v2\/posts\/116\/revisions"}],"predecessor-version":[{"id":122,"href":"https:\/\/t2t2.cc\/index.php?rest_route=\/wp\/v2\/posts\/116\/revisions\/122"}],"wp:attachment":[{"href":"https:\/\/t2t2.cc\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=116"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/t2t2.cc\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=116"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/t2t2.cc\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=116"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}