{"id":65295,"date":"2019-01-25T23:09:47","date_gmt":"2019-01-25T15:09:47","guid":{"rendered":"http:\/\/itteacheritfreelance.hk\/test\/wordpress\/?p=65295"},"modified":"2019-01-25T23:10:01","modified_gmt":"2019-01-25T15:10:01","slug":"c-%e5%b8%b8%e9%87%8f","status":"publish","type":"post","link":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/2019\/01\/25\/c-%e5%b8%b8%e9%87%8f\/","title":{"rendered":"C++ \u5e38\u91cf"},"content":{"rendered":"\n

\"C++ — C\/C++<\/figcaption><\/figure>
常量是固定值，在程序执行期间不会改变。这些固定的值，又叫做**字面量<\/strong>。<\/p>\n\n\n\n**
**常量可以是任何的基本数据类型，可分为整型数字、浮点数字、字符、字符串和布尔值。<\/p>\n\n\n\n**
**常量就像是常规的变量，只不过常量的值在定义后不能进行修改。<\/p>\n\n\n\n**
整数常量<\/h2>\n\n\n\n
整数常量可以是十进制、八进制或十六进制的常量。前缀指定基数：0x 或 0X 表示十六进制，0 表示八进制，不带前缀则默认表示十进制。<\/p>\n\n\n\n
整数常量也可以带一个后缀，后缀是 U 和 L 的组合，U 表示无符号整数（unsigned），L 表示长整数（long）。后缀可以是大写，也可以是小写，U 和 L 的顺序任意。<\/p>\n\n\n\n
下面列举几个整数常量的实例：<\/p>\n\n\n\n
212 \/\/ 合法的\n215u \/\/ 合法的\n0xFeeL \/\/ 合法的\n078 \/\/ 非法的：8 不是八进制的数字\n032UU \/\/ 非法的：不能重复后缀\n<\/pre>\n\n\n\n
以下是各种类型的整数常量的实例：<\/p>\n\n\n\n
85 \/\/ 十进制\n0213 \/\/ 八进制 \n0x4b \/\/ 十六进制 \n30 \/\/ 整数 \n30u \/\/ 无符号整数 \n30l \/\/ 长整数 \n30ul \/\/ 无符号长整数\n<\/pre>\n\n\n\n
浮点常量<\/h2>\n\n\n\n
浮点常量由整数部分、小数点、小数部分和指数部分组成。您可以使用小数形式或者指数形式来表示浮点常量。<\/p>\n\n\n\n
当使用小数形式表示时，必须包含小数点、指数，或同时包含两者。当使用指数形式表示时，必须包含整数部分、小数部分，或同时包含两者。带符号的指数是用 e 或 E 引入的。<\/p>\n\n\n\n
下面列举几个浮点常量的实例：<\/p>\n\n\n\n
3.14159 \/\/ 合法的 \n314159E-5L \/\/ 合法的 \n510E \/\/ 非法的：不完整的指数\n210f \/\/ 非法的：没有小数或指数\n.e55 \/\/ 非法的：缺少整数或分数\n<\/pre>\n\n\n\n
$\"IT電腦補習$
為大家配對電腦補習,IT freelance<\/a>, 私人老師。\n立刻註冊及報名電腦補習課程吧!<\/figcaption><\/figure>
布尔常量<\/h2>\n\n\n\n
布尔常量共有两个，它们都是标准的 C++ 关键字：<\/p>\n\n\n\n
**true<\/strong> 值代表真。<\/li>**
false<\/strong> 值代表假。<\/li><\/ul>
我们不应把 true 的值看成 1，把 false 的值看成 0。<\/p>\n\n\n\n
字符常量<\/h2>\n\n\n\n
字符常量是括在单引号中。如果常量以 L（仅当大写时）开头，则表示它是一个宽字符常量（例如 L’x’），此时它必须存储在 wchar_t<\/strong> 类型的变量中。否则，它就是一个窄字符常量（例如 ‘x’），此时它可以存储在 **char<\/strong> 类型的简单变量中。<\/p>\n\n\n\n**
**字符常量可以是一个普通的字符（例如 ‘x’）、一个转义序列（例如 ‘\\t’），或一个通用的字符（例如 ‘\\u02C0’）。<\/p>\n\n\n\n**
在 C++ 中，有一些特定的字符，当它们前面有反斜杠时，它们就具有特殊的含义，被用来表示如换行符（\\n）或制表符（\\t）等。下表列出了一些这样的转义序列码：<\/p>\n\n\n\n
转义序列<\/th> 含义<\/th><\/tr>
\\\\<\/td> \\ 字符<\/td><\/tr>
\\’<\/td> ‘ 字符<\/td><\/tr>
\\”<\/td> ” 字符<\/td><\/tr>
\\?<\/td> ? 字符<\/td><\/tr>
\\a<\/td> 警报铃声<\/td><\/tr>
\\b<\/td> 退格键<\/td><\/tr>
\\f<\/td> 换页符<\/td><\/tr>
\\n<\/td> 换行符<\/td><\/tr>
\\r<\/td> 回车<\/td><\/tr>
\\t<\/td> 水平制表符<\/td><\/tr>
\\v<\/td> 垂直制表符<\/td><\/tr>
\\ooo<\/td> 一到三位的八进制数<\/td><\/tr>
\\xhh . . .<\/td> 一个或多个数字的十六进制数<\/td><\/tr><\/tbody><\/table>
定义常量<\/h2>\n\n\n\n
在 C++ 中，有两种简单的定义常量的方式：<\/p>\n\n\n\n
使用 **#define<\/strong> 预处理器。<\/li>**
使用 const<\/strong> 关键字。<\/li><\/ul>
#define 预处理器<\/h2>\n\n\n\n
下面是使用 #define 预处理器定义常量的形式：<\/p>\n\n\n\n
#define identifier value\n<\/pre>\n\n\n\n
具体请看下面的实例：<\/p>\n\n\n\n
#include <iostream>\nusing namespace std;\n\n#define LENGTH 10 \n#define WIDTH 5\n#define NEWLINE '\\n'\n\nint main()\n{\n\n int area; \n \n area = LENGTH * WIDTH;\n cout << area;\n cout << NEWLINE;\n return 0;\n}<\/code><\/pre>\n\n\n\n当上面的代码被编译和执行时，它会产生下列结果：<\/p>\n\n\n\n 50\n<\/pre>\n\n\n\nconst 关键字<\/h2>\n\n\n\n您可以使用 const<\/strong> 前缀声明指定类型的常量，如下所示：<\/p>\n\n\n\n const type variable = value;\n<\/pre>\n\n\n\n具体请看下面的实例：<\/p>\n\n\n\n #include <iostream>\nusing namespace std;\n\nint main()\n{\n const int LENGTH = 10;\n const int WIDTH = 5;\n const char NEWLINE = '\\n';\n int area; \n \n area = LENGTH * WIDTH;\n cout << area;\n cout << NEWLINE;\n return 0;\n} <\/code><\/pre>\n\n\n\n当上面的代码被编译和执行时，它会产生下列结果：<\/p>\n\n\n\n 50\n<\/pre>\n\n\n\n请注意，把常量定义为大写字母形式，是一个很好的编程实践。 <\/p>\n\n\n\n <\/figure><\/p>\n <\/p><\/body><\/html>\n","protected":false},"excerpt":{"rendered":" C++ \u5e38\u91cf \n\u5e38\u91cf\u662f\u56fa\u5b9a\u503c\uff0c\u5728\u7a0b\u5e8f\u6267\u884c\u671f\u95f4\u4e0d\u4f1a\u6539\u53d8\u3002\u8fd9\u4e9b\u56fa\u5b9a\u7684\u503c\uff0c\u53c8\u53eb\u505a\u5b57\u9762\u91cf\u3002\u5e38\u91cf\u53ef\u4ee5\u662f\u4efb\u4f55\u7684\u57fa\u672c\u6570\u636e\u7c7b\u578b\uff0c\u53ef\u5206\u4e3a\u6574\u578b\u6570\u5b57\u3001\u6d6e\u70b9\u6570\u5b57\u3001\u5b57\u7b26\u3001\u5b57\u7b26\u4e32\u548c\u5e03\u5c14\u503c\u3002\u5e38\u91cf\u5c31\u50cf\u662f\u5e38\u89c4\u7684\u53d8\u91cf\uff0c\u53ea\u4e0d\u8fc7\u5e38\u91cf\u7684\u503c\u5728\u5b9a\u4e49\u540e\u4e0d\u80fd\u8fdb\u884c\u4fee\u6539\u3002 \u95b1\u8b80\u5168\u6587 →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":175,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"slim_seo":[],"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","enabled":false}}},"categories":[56],"tags":[1536,376,1542,1541,1544,1540,1537,1535,1538,1543,1550,378,377,1539,316,317],"jetpack_publicize_connections":[],"aioseo_notices":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/itteacheritfreelance.hk\/test\/wordpress\/wp-content\/uploads\/2016\/04\/c-c-programming-for-hackers-part-1-introduction.1280x600.jpg?fit=1280%2C600&ssl=1","jetpack_shortlink":"https:\/\/wp.me\/p7prtj-gZ9","jetpack-related-posts":[],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/posts\/65295"}],"collection":[{"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/comments?post=65295"}],"version-history":[{"count":3,"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/posts\/65295\/revisions"}],"predecessor-version":[{"id":65316,"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/posts\/65295\/revisions\/65316"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/media\/175"}],"wp:attachment":[{"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/media?parent=65295"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/categories?post=65295"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/tags?post=65295"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}

C\/C++<\/figcaption><\/figure>
常量是固定值，在程序执行期间不会改变。这些固定的值，又叫做**字面量<\/strong>。<\/p>\n\n\n\n**
**常量可以是任何的基本数据类型，可分为整型数字、浮点数字、字符、字符串和布尔值。<\/p>\n\n\n\n**
**常量就像是常规的变量，只不过常量的值在定义后不能进行修改。<\/p>\n\n\n\n**
整数常量<\/h2>\n\n\n\n
整数常量可以是十进制、八进制或十六进制的常量。前缀指定基数：0x 或 0X 表示十六进制，0 表示八进制，不带前缀则默认表示十进制。<\/p>\n\n\n\n
整数常量也可以带一个后缀，后缀是 U 和 L 的组合，U 表示无符号整数（unsigned），L 表示长整数（long）。后缀可以是大写，也可以是小写，U 和 L 的顺序任意。<\/p>\n\n\n\n
下面列举几个整数常量的实例：<\/p>\n\n\n\n
212 \/\/ 合法的\n215u \/\/ 合法的\n0xFeeL \/\/ 合法的\n078 \/\/ 非法的：8 不是八进制的数字\n032UU \/\/ 非法的：不能重复后缀\n<\/pre>\n\n\n\n
以下是各种类型的整数常量的实例：<\/p>\n\n\n\n
85 \/\/ 十进制\n0213 \/\/ 八进制 \n0x4b \/\/ 十六进制 \n30 \/\/ 整数 \n30u \/\/ 无符号整数 \n30l \/\/ 长整数 \n30ul \/\/ 无符号长整数\n<\/pre>\n\n\n\n
浮点常量<\/h2>\n\n\n\n
浮点常量由整数部分、小数点、小数部分和指数部分组成。您可以使用小数形式或者指数形式来表示浮点常量。<\/p>\n\n\n\n
当使用小数形式表示时，必须包含小数点、指数，或同时包含两者。当使用指数形式表示时，必须包含整数部分、小数部分，或同时包含两者。带符号的指数是用 e 或 E 引入的。<\/p>\n\n\n\n
下面列举几个浮点常量的实例：<\/p>\n\n\n\n
3.14159 \/\/ 合法的 \n314159E-5L \/\/ 合法的 \n510E \/\/ 非法的：不完整的指数\n210f \/\/ 非法的：没有小数或指数\n.e55 \/\/ 非法的：缺少整数或分数\n<\/pre>\n\n\n\n
$\"IT電腦補習$
為大家配對電腦補習,IT freelance<\/a>, 私人老師。\n立刻註冊及報名電腦補習課程吧!<\/figcaption><\/figure>
布尔常量<\/h2>\n\n\n\n
布尔常量共有两个，它们都是标准的 C++ 关键字：<\/p>\n\n\n\n
**true<\/strong> 值代表真。<\/li>**
false<\/strong> 值代表假。<\/li><\/ul>
我们不应把 true 的值看成 1，把 false 的值看成 0。<\/p>\n\n\n\n
字符常量<\/h2>\n\n\n\n
字符常量是括在单引号中。如果常量以 L（仅当大写时）开头，则表示它是一个宽字符常量（例如 L’x’），此时它必须存储在 wchar_t<\/strong> 类型的变量中。否则，它就是一个窄字符常量（例如 ‘x’），此时它可以存储在 **char<\/strong> 类型的简单变量中。<\/p>\n\n\n\n**
**字符常量可以是一个普通的字符（例如 ‘x’）、一个转义序列（例如 ‘\\t’），或一个通用的字符（例如 ‘\\u02C0’）。<\/p>\n\n\n\n**
在 C++ 中，有一些特定的字符，当它们前面有反斜杠时，它们就具有特殊的含义，被用来表示如换行符（\\n）或制表符（\\t）等。下表列出了一些这样的转义序列码：<\/p>\n\n\n\n
转义序列<\/th> 含义<\/th><\/tr>
\\\\<\/td> \\ 字符<\/td><\/tr>
\\’<\/td> ‘ 字符<\/td><\/tr>
\\”<\/td> ” 字符<\/td><\/tr>
\\?<\/td> ? 字符<\/td><\/tr>
\\a<\/td> 警报铃声<\/td><\/tr>
\\b<\/td> 退格键<\/td><\/tr>
\\f<\/td> 换页符<\/td><\/tr>
\\n<\/td> 换行符<\/td><\/tr>
\\r<\/td> 回车<\/td><\/tr>
\\t<\/td> 水平制表符<\/td><\/tr>
\\v<\/td> 垂直制表符<\/td><\/tr>
\\ooo<\/td> 一到三位的八进制数<\/td><\/tr>
\\xhh . . .<\/td> 一个或多个数字的十六进制数<\/td><\/tr><\/tbody><\/table>
定义常量<\/h2>\n\n\n\n
在 C++ 中，有两种简单的定义常量的方式：<\/p>\n\n\n\n
使用 **#define<\/strong> 预处理器。<\/li>**
使用 const<\/strong> 关键字。<\/li><\/ul>
#define 预处理器<\/h2>\n\n\n\n
下面是使用 #define 预处理器定义常量的形式：<\/p>\n\n\n\n
#define identifier value\n<\/pre>\n\n\n\n
具体请看下面的实例：<\/p>\n\n\n\n
#include <iostream>\nusing namespace std;\n\n#define LENGTH 10 \n#define WIDTH 5\n#define NEWLINE '\\n'\n\nint main()\n{\n\n int area; \n \n area = LENGTH * WIDTH;\n cout << area;\n cout << NEWLINE;\n return 0;\n}<\/code><\/pre>\n\n\n\n当上面的代码被编译和执行时，它会产生下列结果：<\/p>\n\n\n\n 50\n<\/pre>\n\n\n\nconst 关键字<\/h2>\n\n\n\n您可以使用 const<\/strong> 前缀声明指定类型的常量，如下所示：<\/p>\n\n\n\n const type variable = value;\n<\/pre>\n\n\n\n具体请看下面的实例：<\/p>\n\n\n\n #include <iostream>\nusing namespace std;\n\nint main()\n{\n const int LENGTH = 10;\n const int WIDTH = 5;\n const char NEWLINE = '\\n';\n int area; \n \n area = LENGTH * WIDTH;\n cout << area;\n cout << NEWLINE;\n return 0;\n} <\/code><\/pre>\n\n\n\n当上面的代码被编译和执行时，它会产生下列结果：<\/p>\n\n\n\n 50\n<\/pre>\n\n\n\n请注意，把常量定义为大写字母形式，是一个很好的编程实践。 <\/p>\n\n\n\n <\/figure><\/p>\n <\/p><\/body><\/html>\n","protected":false},"excerpt":{"rendered":" C++ \u5e38\u91cf \n\u5e38\u91cf\u662f\u56fa\u5b9a\u503c\uff0c\u5728\u7a0b\u5e8f\u6267\u884c\u671f\u95f4\u4e0d\u4f1a\u6539\u53d8\u3002\u8fd9\u4e9b\u56fa\u5b9a\u7684\u503c\uff0c\u53c8\u53eb\u505a\u5b57\u9762\u91cf\u3002\u5e38\u91cf\u53ef\u4ee5\u662f\u4efb\u4f55\u7684\u57fa\u672c\u6570\u636e\u7c7b\u578b\uff0c\u53ef\u5206\u4e3a\u6574\u578b\u6570\u5b57\u3001\u6d6e\u70b9\u6570\u5b57\u3001\u5b57\u7b26\u3001\u5b57\u7b26\u4e32\u548c\u5e03\u5c14\u503c\u3002\u5e38\u91cf\u5c31\u50cf\u662f\u5e38\u89c4\u7684\u53d8\u91cf\uff0c\u53ea\u4e0d\u8fc7\u5e38\u91cf\u7684\u503c\u5728\u5b9a\u4e49\u540e\u4e0d\u80fd\u8fdb\u884c\u4fee\u6539\u3002 \u95b1\u8b80\u5168\u6587 →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":175,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"slim_seo":[],"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","enabled":false}}},"categories":[56],"tags":[1536,376,1542,1541,1544,1540,1537,1535,1538,1543,1550,378,377,1539,316,317],"jetpack_publicize_connections":[],"aioseo_notices":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/itteacheritfreelance.hk\/test\/wordpress\/wp-content\/uploads\/2016\/04\/c-c-programming-for-hackers-part-1-introduction.1280x600.jpg?fit=1280%2C600&ssl=1","jetpack_shortlink":"https:\/\/wp.me\/p7prtj-gZ9","jetpack-related-posts":[],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/posts\/65295"}],"collection":[{"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/comments?post=65295"}],"version-history":[{"count":3,"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/posts\/65295\/revisions"}],"predecessor-version":[{"id":65316,"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/posts\/65295\/revisions\/65316"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/media\/175"}],"wp:attachment":[{"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/media?parent=65295"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/categories?post=65295"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/tags?post=65295"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}

转义序列<\/th>	含义<\/th><\/tr>
\\\\<\/td>	\\ 字符<\/td><\/tr>
\\’<\/td>	‘ 字符<\/td><\/tr>
\\”<\/td>	” 字符<\/td><\/tr>
\\?<\/td>	? 字符<\/td><\/tr>
\\a<\/td>	警报铃声<\/td><\/tr>
\\b<\/td>	退格键<\/td><\/tr>
\\f<\/td>	换页符<\/td><\/tr>
\\n<\/td>	换行符<\/td><\/tr>
\\r<\/td>	回车<\/td><\/tr>
\\t<\/td>	水平制表符<\/td><\/tr>
\\v<\/td>	垂直制表符<\/td><\/tr>
\\ooo<\/td>	一到三位的八进制数<\/td><\/tr>
\\xhh . . .<\/td>	一个或多个数字的十六进制数<\/td><\/tr><\/tbody><\/table> 定义常量<\/h2>\n\n\n\n 在 C++ 中，有两种简单的定义常量的方式：<\/p>\n\n\n\n 使用 #define<\/strong> 预处理器。<\/li> 使用 const<\/strong> 关键字。<\/li><\/ul> #define 预处理器<\/h2>\n\n\n\n 下面是使用 #define 预处理器定义常量的形式：<\/p>\n\n\n\n #define identifier value\n<\/pre>\n\n\n\n 具体请看下面的实例：<\/p>\n\n\n\n #include <iostream>\nusing namespace std;\n\n#define LENGTH 10 \n#define WIDTH 5\n#define NEWLINE '\\n'\n\nint main()\n{\n\n int area; \n \n area = LENGTH * WIDTH;\n cout << area;\n cout << NEWLINE;\n return 0;\n}<\/code><\/pre>\n\n\n\n当上面的代码被编译和执行时，它会产生下列结果：<\/p>\n\n\n\n 50\n<\/pre>\n\n\n\nconst 关键字<\/h2>\n\n\n\n您可以使用 const<\/strong> 前缀声明指定类型的常量，如下所示：<\/p>\n\n\n\n const type variable = value;\n<\/pre>\n\n\n\n具体请看下面的实例：<\/p>\n\n\n\n #include <iostream>\nusing namespace std;\n\nint main()\n{\n const int LENGTH = 10;\n const int WIDTH = 5;\n const char NEWLINE = '\\n';\n int area; \n \n area = LENGTH * WIDTH;\n cout << area;\n cout << NEWLINE;\n return 0;\n} <\/code><\/pre>\n\n\n\n当上面的代码被编译和执行时，它会产生下列结果：<\/p>\n\n\n\n 50\n<\/pre>\n\n\n\n请注意，把常量定义为大写字母形式，是一个很好的编程实践。 <\/p>\n\n\n\n <\/figure><\/p>\n <\/p><\/body><\/html>\n","protected":false},"excerpt":{"rendered":" C++ \u5e38\u91cf \n\u5e38\u91cf\u662f\u56fa\u5b9a\u503c\uff0c\u5728\u7a0b\u5e8f\u6267\u884c\u671f\u95f4\u4e0d\u4f1a\u6539\u53d8\u3002\u8fd9\u4e9b\u56fa\u5b9a\u7684\u503c\uff0c\u53c8\u53eb\u505a\u5b57\u9762\u91cf\u3002\u5e38\u91cf\u53ef\u4ee5\u662f\u4efb\u4f55\u7684\u57fa\u672c\u6570\u636e\u7c7b\u578b\uff0c\u53ef\u5206\u4e3a\u6574\u578b\u6570\u5b57\u3001\u6d6e\u70b9\u6570\u5b57\u3001\u5b57\u7b26\u3001\u5b57\u7b26\u4e32\u548c\u5e03\u5c14\u503c\u3002\u5e38\u91cf\u5c31\u50cf\u662f\u5e38\u89c4\u7684\u53d8\u91cf\uff0c\u53ea\u4e0d\u8fc7\u5e38\u91cf\u7684\u503c\u5728\u5b9a\u4e49\u540e\u4e0d\u80fd\u8fdb\u884c\u4fee\u6539\u3002 \u95b1\u8b80\u5168\u6587 →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":175,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"slim_seo":[],"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","enabled":false}}},"categories":[56],"tags":[1536,376,1542,1541,1544,1540,1537,1535,1538,1543,1550,378,377,1539,316,317],"jetpack_publicize_connections":[],"aioseo_notices":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/itteacheritfreelance.hk\/test\/wordpress\/wp-content\/uploads\/2016\/04\/c-c-programming-for-hackers-part-1-introduction.1280x600.jpg?fit=1280%2C600&ssl=1","jetpack_shortlink":"https:\/\/wp.me\/p7prtj-gZ9","jetpack-related-posts":[],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/posts\/65295"}],"collection":[{"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/comments?post=65295"}],"version-history":[{"count":3,"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/posts\/65295\/revisions"}],"predecessor-version":[{"id":65316,"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/posts\/65295\/revisions\/65316"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/media\/175"}],"wp:attachment":[{"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/media?parent=65295"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/categories?post=65295"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/itteacheritfreelance.hk\/test\/wordpress\/wp-json\/wp\/v2\/tags?post=65295"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}