哪位大佬帮忙解答一下，哭了。

[念此生]

char str[ ]="＼0";和char str[ ]={'\064';}这两个哪一个是正确定义了字符串？为什么？还有"\\\"表示的是什么意思？谢谢

[636f6c696e]

当然是char str[ ]="＼0" 字符串是用一对双引号括起来的字符序列，并用字符型数组来存放

[赵4老师]

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.)

[念此生]

引用 1 楼 636f6c696e 的回复:

当然是char str[ ]="＼0" 字符串是用一对双引号括起来的字符序列，并用字符型数组来存放

第二个不是字符型数组吗

[636f6c696e]

双引号单引号分得清吧

引用 3 楼 念此生 的回复:

[quote=引用 1 楼 636f6c696e 的回复:]
当然是char str[ ]="＼0"
字符串是用一对双引号括起来的字符序列，并用字符型数组来存放

第二个不是字符型数组吗[/quote]

[念此生]

引用 4 楼 636f6c696e的回复:

双引号单引号分得清吧
[quote=引用 3 楼 念此生 的回复:]
[quote=引用 1 楼 636f6c696e 的回复:]
当然是char str[ ]="＼0"
字符串是用一对双引号括起来的字符序列，并用字符型数组来存放

第二个不是字符型数组吗[/quote][/quote] 单引号代表一个字符，所以是字符数组啊呀

[自信男孩]

char str[ ]="＼0";
这个是定义的字符串，判断依据就是字符串需要有结束标识，就是'\0'

[636f6c696e]

你自己定义的？我发的里面有这句话？那你别来问了，你自己认为的就是真理，over

引用 5 楼 念此生 的回复:

[quote=引用 4 楼 636f6c696e的回复:]双引号单引号分得清吧
[quote=引用 3 楼 念此生 的回复:]
[quote=引用 1 楼 636f6c696e 的回复:]
当然是char str[ ]="＼0"
字符串是用一对双引号括起来的字符序列，并用字符型数组来存放

第二个不是字符型数组吗[/quote][/quote]
单引号代表一个字符，所以是字符数组啊呀[/quote]

[念此生]

引用 8 楼 636f6c696e的回复:

你自己定义的？我发的里面有这句话？那你别来问了，你自己认为的就是真理，over
[quote=引用 5 楼 念此生 的回复:]
[quote=引用 4 楼 636f6c696e的回复:]双引号单引号分得清吧
[quote=引用 3 楼 念此生 的回复:]
[quote=引用 1 楼 636f6c696e 的回复:]
当然是char str[ ]="＼0"
字符串是用一对双引号括起来的字符序列，并用字符型数组来存放

第二个不是字符型数组吗[/quote][/quote]
单引号代表一个字符，所以是字符数组啊呀[/quote][/quote] 感觉你回复的和我的没关系啊

[只会C++啊]

char str[ ]="＼0" 这个定义的字符串。字符串以"\0"结尾。
"\\\"这个应该是转义字符，前面第一个\是表示后面的是输出"\\"，这个一般用在地址方面吧

[636f6c696e]

字符串必须有截止符\0，单引号定义没有截止符就不是字符串

[guzl86]

好难呀，希望我不要用到这个东西，也不要看到这个东西。