user-0 提问: 请各位指点迷津，谢谢--

回复:
user: user-1
content: 就这结贴率 就这问题 一看就知道是来蹭作业的  人家一堆英文讽刺你都不知道 着实是可怜人  俗话说:可怜之人必有可恨之处 不知道是真的假的

user: user-2
content: 引用 11 楼 u013340289 的回复:[quote=引用 8 楼 bijiaoben 的回复:] [quote=引用 6 楼 u013340289 的回复:] [quote=引用 5 楼 zhao4zhong1 的回复:] 英语也是一门计算机语言的说。  谢谢你，辛苦写了这么多的解释--可是我的英文不好[/quote] [/quote] 表示是刚自学的--那个开发工具还没安装的呢--让你见笑了 [/quote] 兄弟，赶紧先把环境弄好，咱们这个贵在动手加油

user: user-0
content: 引用 10 楼 u013235485 的回复: char x[] = "56\"a\xab\n"; printf_s("%u",sizeof(x));   单字节字符的情况是7个字节。含 编译器最后添加的一个NULL字符\0。 谢谢。。。

user: user-0
content: 引用 8 楼 bijiaoben 的回复:[quote=引用 6 楼 u013340289 的回复:] [quote=引用 5 楼 zhao4zhong1 的回复:] 英语也是一门计算机语言的说。  谢谢你，辛苦写了这么多的解释--可是我的英文不好[/quote] [/quote] 表示是刚自学的--那个开发工具还没安装的呢--让你见笑了

user: user-3
content: char x[] = "56\"a\xab\n"; printf_s("%u",sizeof(x));   单字节字符的情况是7个字节。含 编译器最后添加的一个NULL字符\0。

user: user-2
content: 2和3这种题拿出来问有意思吗？自己敲进去运行一下，结果不就出来了吗？想知道细节就单步跟踪一下，不就OK了吗？有发帖这功夫，2和3的结果早都出来了。

user: user-2
content: 引用 6 楼 u013340289 的回复:[quote=引用 5 楼 zhao4zhong1 的回复:] 英语也是一门计算机语言的说。  谢谢你，辛苦写了这么多的解释--可是我的英文不好[/quote]

user: user-4
content: 引用 6 楼 u013340289 的回复:[quote=引用 5 楼 zhao4zhong1 的回复:] 英语也是一门计算机语言的说。  谢谢你，辛苦写了这么多的解释--可是我的英文不好[/quote] 指定复制粘贴的说， 你不是有电脑吗，输入进去，运行一下结果就出来啦，呵呵

user: user-0
content: 引用 5 楼 zhao4zhong1 的回复:英语也是一门计算机语言的说。  谢谢你，辛苦写了这么多的解释--可是我的英文不好

user: user-5
content: 英语也是一门计算机语言的说。

user: user-0
content: 引用 1 楼 zhao4zhong1 的回复:C++ Character Constants Character constants are one or more members of the “source character set,” the character set in which a program is written, surrounded by single quotation marks ('). They are used to represent characters in the “execution character set,” the character set on the machine where the program executes.  Microsoft Specific   For Microsoft C++, the source and execution character sets are both ASCII.  END Microsoft Specific  There are three kinds of character constants:   Normal character constants   Multicharacter constants   Wide-character constants  Note   Use wide-character constants in place of multicharacter constants to ensure portability.  Character constants are specified as one or more characters enclosed in single quotation marks. For example:  char ch = 'x';          // Specify normal character constant. int mbch = 'ab';        // Specify system-dependent                         //  multicharacter constant. wchar_t wcch = L'ab';   // Specify wide-character constant.  Note that mbch is of type int. If it were declared as type char, the second byte would not be retained. A multicharacter constant has four meaningful characters; specifying more than four generates an error message.  Syntax  character-constant :  'c-char-sequence' L'c-char-sequence'  c-char-sequence :  c-char c-char-sequence c-char  c-char :  any member of the source character set except the single quotation mark ('), backslash (\), or newline character escape-sequence  escape-sequence :  simple-escape-sequence octal-escape-sequence hexadecimal-escape-sequence  simple-escape-sequence : one of  \' \" \? \\ \a \b \f \n \r \t \v  octal-escape-sequence :  \octal-digit \octal-digit octal-digit \octal-digit octal-digit octal-digit  hexadecimal-escape-sequence :  \xhexadecimal-digit hexadecimal-escape-sequence hexadecimal-digit  Microsoft C++ supports normal, multicharacter, and wide-character constants. Use wide-character constants to specify members of the extended execution character set (for example, to support an international application). Normal character constants have type char, multicharacter constants have type int, and wide-character constants have type wchar_t. (The type wchar_t is defined in the standard include files STDDEF.H, STDLIB.H, and STRING.H. The wide-character functions, however, are prototyped only in STDLIB.H.)  The only difference in specification between normal and wide-character constants is that wide-character constants are preceded by the letter L. For example:  char schar = 'x';               // Normal character constant wchar_t wchar = L'\x81\x19';    // Wide-character constant  Table 1.2 shows reserved or nongraphic characters that are system dependent or not allowed within character constants. These characters should be represented with escape sequences.  Table 1.2   C++ Reserved or Nongraphic Characters  Character ASCII  Representation ASCII  Value Escape Sequence  Newline NL (LF) 10 or 0x0a \n  Horizontal tab HT 9 \t  Vertical tab VT 11 or 0x0b \v  Backspace BS 8 \b  Carriage return CR 13 or 0x0d \r  Formfeed FF 12 or 0x0c \f  Alert BEL 7 \a  Backslash \ 92 or 0x5c \\  Question mark ? 63 or 0x3f \?  Single quotation mark ' 39 or 0x27 \'  Double quotation mark " 34 or 0x22 \"  Octal number ooo — \ooo  Hexadecimal number hhh — \xhhh  Null character NUL 0 \0    If the character following the backslash does not specify a legal escape sequence, the result is implementation defined. In Microsoft C++, the character following the backslash is taken literally, as though the escape were not present, and a level 1 warning (“unrecognized character escape sequence”) is issued.  Octal escape sequences, specified in the form \ooo, consist of a backslash and one, two, or three octal characters. Hexadecimal escape sequences, specified in the form \xhhh, consist of the characters \x followed by a sequence of hexadecimal digits. Unlike octal escape constants, there is no limit on the number of hexadecimal digits in an escape sequence.  Octal escape sequences are terminated by the first character that is not an octal digit, or when three characters are seen. For example:  wchar_t och = L'\076a';  // Sequence terminates at a char    ch = '\233';     // Sequence terminates after 3 characters  Similarly, hexadecimal escape sequences terminate at the first character that is not a hexadecimal digit. Because hexadecimal digits include the letters a through f (and A through F), make sure the escape sequence terminates at the intended digit.  Because the single quotation mark (') encloses character constants, use the escape sequence \' to represent enclosed single quotation marks. The double quotation mark (") can be represented without an escape sequence. The backslash character (\) is a line-continuation character when placed at the end of a line. If you want a backslash character to appear within a character constant, you must type two backslashes in a row (\\). (SeePhases of Translation in the Preprocessor Reference for more information about line continuation.) 谢谢你解答--不过我看不明白，全是英文的

user: user-5
content: C++ String Literals A string literal consists of zero or more characters from the source character set surrounded by double quotation marks ("). A string literal represents a sequence of characters that, taken together, form a null-terminated string.  Syntax  string-literal :  "s-char-sequenceopt" L"s-char-sequenceopt"  s-char-sequence :  s-char s-char-sequence s-char  s-char :  any member of the source character set except the double quotation mark ("), backslash (\), or newline character escape-sequence  C++ strings have these types:   Array of char[n], where n is the length of the string (in characters) plus 1 for the terminating '\0' that marks the end of the string   Array of wchar_t, for wide-character strings  The result of modifying a string constant is undefined. For example:  char *szStr = "1234"; szStr[2] = 'A';      // Results undefined  Microsoft Specific   In some cases, identical string literals can be “pooled” to save space in the executable file. In string-literal pooling, the compiler causes all references to a particular string literal to point to the same location in memory, instead of having each reference point to a separate instance of the string literal. The/Gf compiler option enables string pooling.  END Microsoft Specific  When specifying string literals, adjacent strings are concatenated. Therefore, this declaration:  char szStr[] = "12" "34";  is identical to this declaration:  char szStr[] = "1234";  This concatenation of adjacent strings makes it easy to specify long strings across multiple lines:  cout << "Four score and seven years "         "ago, our forefathers brought forth "         "upon this continent a new nation.";  In the preceding example, the entire string Four score and seven years ago, our forefathers brought forth upon this continent a new nation. is spliced together. This string can also be specified using line splicing as follows:  cout << "Four score and seven years \ ago, our forefathers brought forth \ upon this continent a new nation.";  After all adjacent strings in the constant have been concatenated, the NULL character, '\0', is appended to provide an end-of-string marker for C string-handling functions.  When the first string contains an escape character, string concatenation can yield surprising results. Consider the following two declarations:  char szStr1[] = "\01" "23"; char szStr2[] = "\0123";  Although it is natural to assume that szStr1 and szStr2 contain the same values, the values they actually contain are shown in Figure 1.1.  Figure 1.1   Escapes and String Concatenation    Microsoft Specific   The maximum length of a string literal is approximately 2,048 bytes. This limit applies to strings of type char[] and wchar_t[]. If a string literal consists of parts enclosed in double quotation marks, the preprocessor concatenates the parts into a single string, and for each line concatenated, it adds an extra byte to the total number of bytes.   For example, suppose a string consists of 40 lines with 50 characters per line (2,000 characters), and one line with 7 characters, and each line is surrounded by double quotation marks. This adds up to 2,007 bytes plus one byte for the terminating null character, for a total of 2,008 bytes. On concatenation, an extra character is added to the total number of bytes for each of the first 40 lines. This makes a total of 2,048 bytes. (The extra characters are not actually written to the string.) Note, however, that if line continuations (\) are used instead of double quotation marks, the preprocessor does not add an extra character for each line.  END Microsoft Specific  Determine the size of string objects by counting the number of characters and adding 1 for the terminating '\0' or 2 for type wchar_t.  Because the double quotation mark (") encloses strings, use the escape sequence (\") to represent enclosed double quotation marks. The single quotation mark (') can be represented without an escape sequence. The backslash character (\) is a line-continuation character when placed at the end of a line. If you want a backslash character to appear within a string, you must type two backslashes (\\). (SeePhases of Translation in the Preprocessor Reference for more information about line continuation.)  To specify a string of type wide-character (wchar_t[]), precede the opening double quotation mark with the character L. For example:  wchar_t wszStr[] = L"1a1g";  All normal escape codes listed in Character Constants are valid in string constants. For example:  cout << "First line\nSecond line"; cout << "Error! Take corrective action\a";  Because the escape code terminates at the first character that is not a hexadecimal digit, specification of string constants with embedded hexadecimal escape codes can cause unexpected results. The following example is intended to create a string literal containing ASCII 5, followed by the characters five:  \x05five"  The actual result is a hexadecimal 5F, which is the ASCII code for an underscore, followed by the characters ive. The following example produces the desired results:   "\005five"     // Use octal constant. "\x05" "five"  // Use string splicing.

user: user-0
content: 大家是不是 因为 我问的问题太简单了--不回复的哇--真心求解。。。。

user: user-5
content: C++ Character Constants Character constants are one or more members of the “source character set,” the character set in which a program is written, surrounded by single quotation marks ('). They are used to represent characters in the “execution character set,” the character set on the machine where the program executes.  Microsoft Specific   For Microsoft C++, the source and execution character sets are both ASCII.  END Microsoft Specific  There are three kinds of character constants:   Normal character constants   Multicharacter constants   Wide-character constants  Note   Use wide-character constants in place of multicharacter constants to ensure portability.  Character constants are specified as one or more characters enclosed in single quotation marks. For example:  char ch = 'x';          // Specify normal character constant. int mbch = 'ab';        // Specify system-dependent                         //  multicharacter constant. wchar_t wcch = L'ab';   // Specify wide-character constant.  Note that mbch is of type int. If it were declared as type char, the second byte would not be retained. A multicharacter constant has four meaningful characters; specifying more than four generates an error message.  Syntax  character-constant :  'c-char-sequence' L'c-char-sequence'  c-char-sequence :  c-char c-char-sequence c-char  c-char :  any member of the source character set except the single quotation mark ('), backslash (\), or newline character escape-sequence  escape-sequence :  simple-escape-sequence octal-escape-sequence hexadecimal-escape-sequence  simple-escape-sequence : one of  \' \" \? \\ \a \b \f \n \r \t \v  octal-escape-sequence :  \octal-digit \octal-digit octal-digit \octal-digit octal-digit octal-digit  hexadecimal-escape-sequence :  \xhexadecimal-digit hexadecimal-escape-sequence hexadecimal-digit  Microsoft C++ supports normal, multicharacter, and wide-character constants. Use wide-character constants to specify members of the extended execution character set (for example, to support an international application). Normal character constants have type char, multicharacter constants have type int, and wide-character constants have type wchar_t. (The type wchar_t is defined in the standard include files STDDEF.H, STDLIB.H, and STRING.H. The wide-character functions, however, are prototyped only in STDLIB.H.)  The only difference in specification between normal and wide-character constants is that wide-character constants are preceded by the letter L. For example:  char schar = 'x';               // Normal character constant wchar_t wchar = L'\x81\x19';    // Wide-character constant  Table 1.2 shows reserved or nongraphic characters that are system dependent or not allowed within character constants. These characters should be represented with escape sequences.  Table 1.2   C++ Reserved or Nongraphic Characters  Character ASCII  Representation ASCII  Value Escape Sequence  Newline NL (LF) 10 or 0x0a \n  Horizontal tab HT 9 \t  Vertical tab VT 11 or 0x0b \v  Backspace BS 8 \b  Carriage return CR 13 or 0x0d \r  Formfeed FF 12 or 0x0c \f  Alert BEL 7 \a  Backslash \ 92 or 0x5c \\  Question mark ? 63 or 0x3f \?  Single quotation mark ' 39 or 0x27 \'  Double quotation mark " 34 or 0x22 \"  Octal number ooo — \ooo  Hexadecimal number hhh — \xhhh  Null character NUL 0 \0    If the character following the backslash does not specify a legal escape sequence, the result is implementation defined. In Microsoft C++, the character following the backslash is taken literally, as though the escape were not present, and a level 1 warning (“unrecognized character escape sequence”) is issued.  Octal escape sequences, specified in the form \ooo, consist of a backslash and one, two, or three octal characters. Hexadecimal escape sequences, specified in the form \xhhh, consist of the characters \x followed by a sequence of hexadecimal digits. Unlike octal escape constants, there is no limit on the number of hexadecimal digits in an escape sequence.  Octal escape sequences are terminated by the first character that is not an octal digit, or when three characters are seen. For example:  wchar_t och = L'\076a';  // Sequence terminates at a char    ch = '\233';     // Sequence terminates after 3 characters  Similarly, hexadecimal escape sequences terminate at the first character that is not a hexadecimal digit. Because hexadecimal digits include the letters a through f (and A through F), make sure the escape sequence terminates at the intended digit.  Because the single quotation mark (') encloses character constants, use the escape sequence \' to represent enclosed single quotation marks. The double quotation mark (") can be represented without an escape sequence. The backslash character (\) is a line-continuation character when placed at the end of a line. If you want a backslash character to appear within a character constant, you must type two backslashes in a row (\\). (SeePhases of Translation in the Preprocessor Reference for more information about line continuation.)