A character literal is a type of
literal in
programming for the representation of a single
character's value within the
source code
In computing, source code, or simply code, is any collection of code, with or without comments, written using a human-readable programming language, usually as plain text. The source code of a program is specially designed to facilitate the w ...
of a
computer program
A computer program is a sequence or set of instructions in a programming language for a computer to execute. Computer programs are one component of software, which also includes documentation and other intangible components.
A computer program ...
.
Languages that have a dedicated character data type generally include character literals; these include
C,
C++
C++ (pronounced "C plus plus") is a high-level general-purpose programming language created by Danish computer scientist Bjarne Stroustrup as an extension of the C programming language, or "C with Classes". The language has expanded significan ...
,
Java
Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's mos ...
, and
Visual Basic Visual Basic is a name for a family of programming languages from Microsoft. It may refer to:
* Visual Basic .NET (now simply referred to as "Visual Basic"), the current version of Visual Basic launched in 2002 which runs on .NET
* Visual Basic ( ...
. Languages without character data types (like
Python
Python may refer to:
Snakes
* Pythonidae, a family of nonvenomous snakes found in Africa, Asia, and Australia
** ''Python'' (genus), a genus of Pythonidae found in Africa and Asia
* Python (mythology), a mythical serpent
Computing
* Python (pro ...
or
PHP
PHP is a general-purpose scripting language geared toward web development. It was originally created by Danish-Canadian programmer Rasmus Lerdorf in 1993 and released in 1995. The PHP reference implementation is now produced by The PHP Group. ...
) will typically use strings of length 1 to serve the same purpose a character data type would fulfil. This simplifies the implementation and basic usage of a language but also introduces new scope for programming errors.
A common convention for expressing a character literal is to use a single quote (
') for character literals, as contrasted by the use of a double quote (
") for
string literal
A string literal or anonymous string is a string value in the source code of a computer program. Modern programming languages commonly use a quoted sequence of characters, formally " bracketed delimiters", as in x = "foo", where "foo" is a string ...
s. For example,
'a' indicates the single character
a while
"a" indicates the string
a of length 1.
The representation of a character within the computer memory, in storage, and in data transmission, is dependent on a particular
character encoding scheme. For example, an
ASCII
ASCII ( ), abbreviated from American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. Because ...
(or
extended ASCII) scheme will use a single byte of computer memory, while a
UTF-8
UTF-8 is a variable-length character encoding used for electronic communication. Defined by the Unicode Standard, the name is derived from ''Unicode'' (or ''Universal Coded Character Set'') ''Transformation Format 8-bit''.
UTF-8 is capable of ...
scheme will use one or more bytes, depending on the particular character being encoded.
Alternative ways to encode character values include specifying an integer value for a code point, such as an ASCII code value or a Unicode code point. This may be done directly via converting an integer literal to a character, or via an
escape sequence
In computer science, an escape sequence is a combination of characters that has a meaning other than the literal characters contained therein; it is marked by one or more preceding (and possibly terminating) characters.
Examples
* In C and ma ...
.
See also
*
String literal
A string literal or anonymous string is a string value in the source code of a computer program. Modern programming languages commonly use a quoted sequence of characters, formally " bracketed delimiters", as in x = "foo", where "foo" is a string ...
*
XML Literals
* – for multicharacter literals
References
{{Reflist, 30em
Character encoding
Data types