Escape sequences are used to represent certain special characters withinstring literals andcharacter constants.
The following escape sequences are available. ISO C requires a diagnostic if the backslash is followed by any character not listed here:
| Escape sequence | Description | Representation |
|---|---|---|
| Simple escape sequences | ||
\' | single quote | byte0x27 in ASCII encoding |
\" | double quote | byte0x22 in ASCII encoding |
\? | question mark | byte0x3f in ASCII encoding |
\\ | backslash | byte0x5c in ASCII encoding |
\a | audible bell | byte0x07 in ASCII encoding |
\b | backspace | byte0x08 in ASCII encoding |
\f | form feed - new page | byte0x0c in ASCII encoding |
\n | line feed - new line | byte0x0a in ASCII encoding |
\r | carriage return | byte0x0d in ASCII encoding |
\t | horizontal tab | byte0x09 in ASCII encoding |
\v | vertical tab | byte0x0b in ASCII encoding |
| Numeric escape sequences | ||
\nnn | arbitrary octal value | code unitnnn |
\xn... | arbitrary hexadecimal value | code unitn... (arbitrary number of hexadecimal digits) |
| Universal character names | ||
\unnnn(since C99) | Unicode value in allowed range; may result in several code units | code pointU+nnnn |
\Unnnnnnnn(since C99) | Unicode value in allowed range; may result in several code units | code pointU+nnnnnnnn |
Range of universal character namesIf a universal character name corresponds to a code point that is not | (since C99) |
\0 is the most commonly used octal escape sequence, because it represents the terminating null character in null-terminated strings.
The new-line character\n has special meaning when used intext mode I/O: it is converted to the OS-specific newline byte or byte sequence.
Octal escape sequences have a length limit of three octal digits but terminate at the first character that is not a valid octal digit if encountered sooner.
Hexadecimal escape sequences have no length limit and terminate at the first character that is not a valid hexadecimal digit. If the value represented by a single hexadecimal escape sequence does not fit the range of values represented by the character type used in this string literal or character constant (char,char8_t(since C23),char16_t,char32_t(since C11), orwchar_t), the result is unspecified.
A universal character name in a narrow string literalor a 16-bit string literal(since C11) may map to more than one code unit, e.g.\U0001f34c is 4char code units in UTF-8 (\xF0\x9F\x8D\x8C) and 2char16_t code units in UTF-16 (\xD83C\xDF4C)(since C11). | (since C99) |
A universal character name corresponding to a code pointer greater than | (since C99) (until C23) |
The question mark escape sequence\? is used to preventtrigraphs from being interpreted inside string literals: a string such as"??/" is compiled as"\", but if the second question mark is escaped, as in"?\?/", it becomes"??/" | (until C23) |
#include <stdio.h> int main(void){printf("This\nis\na\ntest\n\nShe said,\"How are you?\"\n");}
Output:
Thisisatest She said, "How are you?"
C++ documentation forEscape sequences |
