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Each string ends at the first occurrence of the zero code unit of the appropriate kind (char or wchar_t).Consequently, a byte string (char*) can contain non-NUL characters in ASCII or any ASCII extension, but not characters in encodings such as UTF-16 (even though a 16-bit code unit might be nonzero, its high or low byte might be zero).
The std::string class is the standard representation for a text string since C++98. The class provides some typical string operations like comparison, concatenation, find and replace, and a function for obtaining substrings. An std::string can be constructed from a C-style string, and a C-style string can also be obtained from one. [7]
The only popular alternative at that time, usually called a "Pascal string" (a more modern term is "length-prefixed"), used a leading byte to store the length of the string. This allows the string to contain NUL and made finding the length need only one memory access (O(1) (constant) time ), but limited string length to 255 characters.
UTF-8 (u8) character literals [10] [13] (UTF-8 string literals have existed since C++11; C++17 adds the corresponding character literals for consistency, though as they are restricted to a single byte they can only store "Basic Latin" and C0 control codes, i.e. ASCII) Hexadecimal floating-point literals [14] [15]
Byte values can be expressed in hexadecimal with the prefix \x followed by two hex digits: '\x1B' represents the Esc control character; "\x1B[0m\x1B[25;1H" is a string containing 11 characters with two embedded Esc characters. [3] To output an integer as hexadecimal with the printf function family, the format conversion code %X or %x is used.
Set all bytes in a block of memory to a given byte value. Base instruction 0xFE 0x15 initobj <typeTok> Initialize the value at address dest. Object model instruction 0x75 isinst <class> Test if obj is an instance of class, returning null or an instance of that class or interface. Object model instruction 0x27 jmp <method>
In most encodings, this is translated to a single code unit with a zero value. For instance, in UTF-8 it is a single zero byte. However, in Modified UTF-8 the null character is encoded as two bytes: 0xC0,0x80. This allows the byte with the value of zero, which is now not used for any character, to be used as a string terminator.
Sequence \n maps to one byte, despite the fact that the platform may use more than one byte to denote a newline, such as the DOS/Windows CRLF sequence, 0x0D 0x0A. The translation from 0x0A to 0x0D 0x0A on DOS and Windows occurs when the byte is written out to a file or to the console, and the inverse translation is done when text files are read.