{"id":312,"date":"2006-09-08T17:30:07","date_gmt":"2006-09-08T09:30:07","guid":{"rendered":"https:\/\/t.n-years.com\/?p=312"},"modified":"2021-01-06T19:39:09","modified_gmt":"2021-01-06T11:39:09","slug":"%e8%81%8c%e4%b8%9aextern%e5%a3%b0%e6%98%8e%e8%be%a8%e6%9e%90","status":"publish","type":"post","link":"https:\/\/t.n-years.com\/?p=312","title":{"rendered":"[\u804c\u4e1a]extern\u58f0\u660e\u8fa8\u6790"},"content":{"rendered":"

extern\u58f0\u660e\u8fa8\u6790<\/FONT><\/STRONG><\/P>
\n

extern\u53ef\u4ee5\u7f6e\u4e8e\u53d8\u91cf\u6216\u8005\u51fd\u6570\u524d\uff0c\u4ee5\u6807\u793a\u53d8\u91cf\u6216\u8005\u51fd\u6570\u7684\u5b9a\u4e49\u5728\u522b\u7684\u6587\u4ef6\u4e2d<\/FONT><\/SPAN><\/P>
\n

1 \u57fa\u672c\u89e3\u91ca

<\/STRONG>\u3000\u3000extern\u53ef\u4ee5\u7f6e\u4e8e\u53d8\u91cf\u6216\u8005\u51fd\u6570\u524d\uff0c\u4ee5\u6807\u793a\u53d8\u91cf\u6216\u8005\u51fd\u6570\u7684\u5b9a\u4e49\u5728\u522b\u7684\u6587\u4ef6\u4e2d\uff0c\u63d0\u793a\u7f16\u8bd1\u5668\u9047\u5230\u6b64\u53d8\u91cf\u548c\u51fd\u6570\u65f6\u5728\u5176\u4ed6\u6a21\u5757\u4e2d\u5bfb\u627e\u5176\u5b9a\u4e49\u3002

\u3000\u3000\u53e6\u5916\uff0cextern\u4e5f\u53ef\u7528\u6765\u8fdb\u884c\u94fe\u63a5\u6307\u5b9a\u3002<\/FONT>
2 \u95ee\u9898\uff1aextern \u53d8\u91cf

<\/STRONG>\u3000\u3000\u5728\u4e00\u4e2a\u6e90\u6587\u4ef6\u91cc\u5b9a\u4e49\u4e86\u4e00\u4e2a\u6570\u7ec4\uff1a

<\/FONT>
\n
\n
\n
\n
char a[6];<\/TD><\/TR><\/TBODY><\/TABLE>
\u3000\u3000\u5728\u53e6\u5916\u4e00\u4e2a\u6587\u4ef6\u91cc\u7528\u4e0b\u5217\u8bed\u53e5\u8fdb\u884c\u4e86\u58f0\u660e\uff1a


\n
\n
\n
\n
extern char *a\uff1b<\/TD><\/TR><\/TBODY><\/TABLE>
\u3000\u3000\u8bf7\u95ee\uff0c\u8fd9\u6837\u53ef\u4ee5\u5417\uff1f

\u3000\u3000\u7b54\u6848\u4e0e\u5206\u6790\uff1a

\u3000\u30001)\u3001\u4e0d\u53ef\u4ee5\uff0c\u7a0b\u5e8f\u8fd0\u884c\u65f6\u4f1a\u544a\u8bc9\u4f60\u975e\u6cd5\u8bbf\u95ee\u3002\u539f\u56e0\u5728\u4e8e\uff0c\u6307\u5411\u7c7b\u578bT\u7684\u6307\u9488\u5e76\u4e0d\u7b49\u4ef7\u4e8e\u7c7b\u578bT\u7684\u6570\u7ec4\u3002extern char *a\u58f0\u660e\u7684\u662f\u4e00\u4e2a\u6307\u9488\u53d8\u91cf\u800c\u4e0d\u662f\u5b57\u7b26\u6570\u7ec4\uff0c\u56e0\u6b64\u4e0e\u5b9e\u9645\u7684\u5b9a\u4e49\u4e0d\u540c\uff0c\u4ece\u800c\u9020\u6210\u8fd0\u884c\u65f6\u975e\u6cd5\u8bbf\u95ee\u3002\u5e94\u8be5\u5c06\u58f0\u660e\u6539\u4e3aextern char a[ ]\u3002

\u3000\u30002)\u3001\u4f8b\u5b50\u5206\u6790\u5982\u4e0b\uff0c\u5982\u679ca[] = \"abcd\",\u5219\u5916\u90e8\u53d8\u91cfa=0x61626364 (abcd\u7684ASCII\u7801\u503c)\uff0c*a\u663e\u7136\u6ca1\u6709\u610f\u4e49\uff0c\u5982\u4e0b\u56fe\uff1a


\n
\n
\n
\n

\n
\"\"<\/DIV><\/TD><\/TR><\/TBODY><\/TABLE>
\u3000\u3000\u663e\u7136a\u6307\u5411\u7684\u7a7a\u95f4\uff080x61626364\uff09\u6ca1\u6709\u610f\u4e49\uff0c\u6613\u51fa\u73b0\u975e\u6cd5\u5185\u5b58\u8bbf\u95ee\u3002

\u3000\u30003)\u3001\u8fd9\u63d0\u793a\u6211\u4eec\uff0c\u5728\u4f7f\u7528extern\u65f6\u5019\u8981\u4e25\u683c\u5bf9\u5e94\u58f0\u660e\u65f6\u7684\u683c\u5f0f\uff0c\u5728\u5b9e\u9645\u7f16\u7a0b\u4e2d\uff0c\u8fd9\u6837\u7684\u9519\u8bef\u5c61\u89c1\u4e0d\u9c9c\u3002

\u3000\u30004)\u3001extern\u7528\u5728\u53d8\u91cf\u58f0\u660e\u4e2d\u5e38\u5e38\u6709\u8fd9\u6837\u4e00\u4e2a\u4f5c\u7528\uff0c\u4f60\u5728*.c\u6587\u4ef6\u4e2d\u58f0\u660e\u4e86\u4e00\u4e2a\u5168\u5c40\u7684\u53d8\u91cf\uff0c\u8fd9\u4e2a\u5168\u5c40\u7684\u53d8\u91cf\u5982\u679c\u8981\u88ab\u5f15\u7528\uff0c\u5c31\u653e\u5728*.h\u4e2d\u5e76\u7528extern\u6765\u58f0\u660e\u3002

\u3000\u30003 \u95ee\u9898\uff1aextern \u51fd\u65701<\/STRONG>

\u3000\u3000\u5e38\u5e38\u89c1extern\u653e\u5728\u51fd\u6570\u7684\u524d\u9762\u6210\u4e3a\u51fd\u6570\u58f0\u660e\u7684\u4e00\u90e8\u5206\uff0c\u90a3\u4e48\uff0cC\u8bed\u8a00\u7684\u5173\u952e\u5b57extern\u5728\u51fd\u6570\u7684\u58f0\u660e\u4e2d\u8d77\u4ec0\u4e48\u4f5c\u7528\uff1f

\u3000\u3000\u7b54\u6848\u4e0e\u5206\u6790\uff1a

\u3000\u3000\u5982\u679c\u51fd\u6570\u7684\u58f0\u660e\u4e2d\u5e26\u6709\u5173\u952e\u5b57extern\uff0c\u4ec5\u4ec5\u662f\u6697\u793a\u8fd9\u4e2a\u51fd\u6570\u53ef\u80fd\u5728\u522b\u7684\u6e90\u6587\u4ef6\u91cc\u5b9a\u4e49\uff0c\u6ca1\u6709\u5176\u5b83\u4f5c\u7528\u3002\u5373\u4e0b\u8ff0\u4e24\u4e2a\u51fd\u6570\u58f0\u660e\u6ca1\u6709\u660e\u663e\u7684\u533a\u522b\uff1a


\n
\n
\n
\n
extern int f(); \u548cint f();<\/TD><\/TR><\/TBODY><\/TABLE>
\u3000\u3000\u5f53\u7136\uff0c\u8fd9\u6837\u7684\u7528\u5904\u8fd8\u662f\u6709\u7684\uff0c\u5c31\u662f\u5728\u7a0b\u5e8f\u4e2d\u53d6\u4ee3include \u201c*.h\u201d\u6765\u58f0\u660e\u51fd\u6570\uff0c\u5728\u4e00\u4e9b\u590d\u6742\u7684\u9879\u76ee\u4e2d\uff0c\u6211\u6bd4\u8f83\u4e60\u60ef\u5728\u6240\u6709\u7684\u51fd\u6570\u58f0\u660e\u524d\u6dfb\u52a0extern\u4fee\u9970\u3002

\u3000\u30004 \u95ee\u9898\uff1aextern \u51fd\u65702<\/STRONG>

\u3000\u3000\u5f53\u51fd\u6570\u63d0\u4f9b\u65b9\u5355\u65b9\u9762\u4fee\u6539\u51fd\u6570\u539f\u578b\u65f6\uff0c\u5982\u679c\u4f7f\u7528\u65b9\u4e0d\u77e5\u60c5\u7ee7\u7eed\u6cbf\u7528\u539f\u6765\u7684extern\u7533\u660e\uff0c\u8fd9\u6837\u7f16\u8bd1\u65f6\u7f16\u8bd1\u5668\u4e0d\u4f1a\u62a5\u9519\u3002\u4f46\u662f\u5728\u8fd0\u884c\u8fc7\u7a0b\u4e2d\uff0c\u56e0\u4e3a\u5c11\u4e86\u6216\u8005\u591a\u4e86\u8f93\u5165\u53c2\u6570\uff0c\u5f80\u5f80\u4f1a\u7167\u6210\u7cfb\u7edf\u9519\u8bef\uff0c\u8fd9\u79cd\u60c5\u51b5\u5e94\u8be5\u5982\u4f55\u89e3\u51b3\uff1f

\u3000\u3000\u7b54\u6848\u4e0e\u5206\u6790\uff1a

\u3000\u3000\u76ee\u524d\u4e1a\u754c\u9488\u5bf9\u8fd9\u79cd\u60c5\u51b5\u7684\u5904\u7406\u6ca1\u6709\u4e00\u4e2a\u5f88\u5b8c\u7f8e\u7684\u65b9\u6848\uff0c\u901a\u5e38\u7684\u505a\u6cd5\u662f\u63d0\u4f9b\u65b9\u5728\u81ea\u5df1\u7684xxx_pub.h\u4e2d\u63d0\u4f9b\u5bf9\u5916\u90e8\u63a5\u53e3\u7684\u58f0\u660e\uff0c\u7136\u540e\u8c03\u7528\u65b9include\u8be5\u5934\u6587\u4ef6\uff0c\u4ece\u800c\u7701\u53bbextern\u8fd9\u4e00\u6b65\u3002\u4ee5\u907f\u514d\u8fd9\u79cd\u9519\u8bef\u3002

\u3000\u3000\u5b9d\u5251\u6709\u53cc\u950b\uff0c\u5bf9extern\u7684\u5e94\u7528\uff0c\u4e0d\u540c\u7684\u573a\u5408\u5e94\u8be5\u9009\u62e9\u4e0d\u540c\u7684\u505a\u6cd5\u3002

\u3000\u30005 \u95ee\u9898\uff1aextern \u201cC\u201d<\/STRONG>

\u3000\u3000\u5728C++\u73af\u5883\u4e0b\u4f7f\u7528C\u51fd\u6570\u7684\u65f6\u5019\uff0c\u5e38\u5e38\u4f1a\u51fa\u73b0\u7f16\u8bd1\u5668\u65e0\u6cd5\u627e\u5230obj\u6a21\u5757\u4e2d\u7684C\u51fd\u6570\u5b9a\u4e49\uff0c\u4ece\u800c\u5bfc\u81f4\u94fe\u63a5\u5931\u8d25\u7684\u60c5\u51b5\uff0c\u5e94\u8be5\u5982\u4f55\u89e3\u51b3\u8fd9\u79cd\u60c5\u51b5\u5462\uff1f

\u3000\u3000\u7b54\u6848\u4e0e\u5206\u6790\uff1a

\u3000\u3000C++\u8bed\u8a00\u5728\u7f16\u8bd1\u7684\u65f6\u5019\u4e3a\u4e86\u89e3\u51b3\u51fd\u6570\u7684\u591a\u6001\u95ee\u9898\uff0c\u4f1a\u5c06\u51fd\u6570\u540d\u548c\u53c2\u6570\u8054\u5408\u8d77\u6765\u751f\u6210\u4e00\u4e2a\u4e2d\u95f4\u7684\u51fd\u6570\u540d\u79f0\uff0c\u800cC\u8bed\u8a00\u5219\u4e0d\u4f1a\uff0c\u56e0\u6b64\u4f1a\u9020\u6210\u94fe\u63a5\u65f6\u627e\u4e0d\u5230\u5bf9\u5e94\u51fd\u6570\u7684\u60c5\u51b5\uff0c\u6b64\u65f6C\u51fd\u6570\u5c31\u9700\u8981\u7528extern \u201cC\u201d\u8fdb\u884c\u94fe\u63a5\u6307\u5b9a\uff0c\u8fd9\u544a\u8bc9\u7f16\u8bd1\u5668\uff0c\u8bf7\u4fdd\u6301\u6211\u7684\u540d\u79f0\uff0c\u4e0d\u8981\u7ed9\u6211\u751f\u6210\u7528\u4e8e\u94fe\u63a5\u7684\u4e2d\u95f4\u51fd\u6570\u540d\u3002

\u3000\u3000\u4e0b\u9762\u662f\u4e00\u4e2a\u6807\u51c6\u7684\u5199\u6cd5\uff1a


\n
\n
\n
\n
\/\/\u5728.h\u6587\u4ef6\u7684\u5934\u4e0a
#ifdef __cplusplus
#if __cplusplus
extern \"C\"{
\u3000#endif
\u3000#endif \/* __cplusplus *\/
\u3000\u2026
\u3000\u2026
\u3000\/\/.h\u6587\u4ef6\u7ed3\u675f\u7684\u5730\u65b9
\u3000#ifdef __cplusplus
\u3000#if __cplusplus
}
#endif
#endif \/* __cplusplus *\/<\/TD><\/TR><\/TBODY><\/TABLE><\/P><\/p>\n","protected":false},"excerpt":{"rendered":"

extern\u58f0\u660e\u8fa8\u6790 extern\u53ef\u4ee5\u7f6e\u4e8e\u53d8\u91cf\u6216\u8005\u51fd\u6570\u524d\uff0c\u4ee5\u6807\u793a\u53d8\u91cf\u6216\u8005\u51fd\u6570\u7684\u5b9a\u4e49\u5728\u522b\u7684\u6587\u4ef6\u4e2d 1 \u57fa\u672c\u89e3\u91ca\u3000… <\/p>\n

\u9605\u8bfb\u66f4\u591a<\/i><\/a><\/div>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-312","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/t.n-years.com\/index.php?rest_route=\/wp\/v2\/posts\/312","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/t.n-years.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/t.n-years.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/t.n-years.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/t.n-years.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=312"}],"version-history":[{"count":1,"href":"https:\/\/t.n-years.com\/index.php?rest_route=\/wp\/v2\/posts\/312\/revisions"}],"predecessor-version":[{"id":2547,"href":"https:\/\/t.n-years.com\/index.php?rest_route=\/wp\/v2\/posts\/312\/revisions\/2547"}],"wp:attachment":[{"href":"https:\/\/t.n-years.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=312"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/t.n-years.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=312"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/t.n-years.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=312"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}