c++ literal formats

Question

c++ literal formats

Stewart Patch 20

what are the formats for C++ character literals of type wchar_t

Answer accepted by question author

2 additional answers

Your answer

Answer 1

Hi @Stewart Patch ,

Thanks for reaching out.

In C++, a character literal of type wchar_t is written using the L prefix in front of the character. That prefix tells the compiler you want a wide character instead of a regular char.

The basic format is:

L'character'

For example:

wchar_t ch1 = L'A';
wchar_t ch2 = L'中';

Both are valid wide character literals. The L is what makes the literal type wchar_t.

You can also use escape sequences the same way you would with normal character literals:

wchar_t newline = L'\n';
wchar_t hexChar = L'\x4E2D';
wchar_t unicode = L'\u4E2D';

A couple of important notes:

The literal must contain exactly one character (after escape processing).
The actual size of wchar_t depends on the platform (commonly 2 bytes on Windows and 4 bytes on many Unix/Linux systems).

For more details, as RLWA32 has mentioned, you can refer to this document.

Hope this helps! If my answer was helpful - kindly follow the instructions here so others with the same problem can benefit as well.

Answer 2

RLWA32 52,266

Refer to the documentation at String and character literals

Answer 3

For character literals of type wchar_t in C++, use the wide-character literal form:

wchar_t c1 = L'a';      // simple wide character
wchar_t c2 = L'\n';     // escape sequence
wchar_t c3 = L'\x41';   // hex escape (A)
wchar_t c4 = L'\u03A9'; // universal character name (Ω), if representable

Key points from the formats:

Prefix
- L prefix before the quotes: L'…' creates a wide-character literal of type wchar_t.
Contents allowed inside L'…'
- A single ordinary character: L'a', L'Z'.
- An escape sequence:
  - Standard escapes like L'\n', L'\t', L'\\', L'\''.
  - Octal escapes: backslash + 1–3 octal digits, e.g. L'\101'.
  - Hex escapes: \x + 1 or more hex digits, e.g. L'\x41'.
    - For L-prefixed literals, the highest allowed hex value is 0xFFFF.
- Universal character names (for Unicode code points representable in wchar_t): L'\uXXXX' or L'\UXXXXXXXX' (subject to implementation limits and representation).
Type and value
- A wide-character literal with a single character/escape/universal character name has type wchar_t.
- Its value is the numerical value of its encoding in the execution wide-character set, unless the character has no representation there (then the value is implementation-defined).
Multicharacter wide literals
- If a wide-character literal contains multiple characters/escapes/universal character names, the value is implementation-defined.
Related wide string form (for completeness)
- Wide-character string literals use L"…" and have type const wchar_t*, e.g. L"hello".

References:

Share via

c++ literal formats

2 additional answers

Your answer