0
0
Section 2. Fundamentals. 2.3 C# Constants and Literals
The constants refer to unchangeable and read-only (fixed) values that the program may not alter during its execution. They are also called literals. Constants can be of any of the basic data types like an integer constant, a floating constant, a character constant, or a string literal. There are also enumeration constants as well.
The constants are treated just like regular variables except that their values cannot be modified after their definition.
You cannot declare a constant variable without assigning the value. If you do, an error will occur: A const field requires a value to be provided.
Integer Literals
An integer literal can be a decimal, or hexadecimal constant. A prefix specifies the base or radix: 0x or 0X for hexadecimal, and there is no prefix id for decimal.
An integer literal can also have a suffix that is a combination of U and L, for unsigned and long, respectively. The suffix can be uppercase or lowercase and can be in any order.
Following are other examples of various types of Integer literals −
- 45 /* decimal /
- 0x2a / hexadecimal /
- 20 / int /
- 10u / unsigned int /
- 10l / long /
- 10ul / unsigned long */
Floating-point Literals
A floating-point literal has an integer part, a decimal point, a fractional part, and an exponent part. You can represent floating point literals either in decimal form or exponential form.
While representing in decimal form, you must include the decimal point, the exponent, or both; and while representing using exponential form you must include the integer part, the fractional part, or both. The signed exponent is introduced by e or E.
The examples of floating-point literals:
- 3.14159
- 314159E-5F
Character Constants
Character literals are enclosed in single quotes. For example, ‘x’ and can be stored in a simple variable of char type. A character literal can be a plain character (such as ‘x’), an escape sequence (such as ‘\t’), or a universal character (such as ‘\u02C0’).
There are certain characters in C# when they are preceded by a backslash. They have special meaning and they are used to represent like newline (\n) or tab (\t).
| Escape sequence | Meaning |
|---|---|
| \\ | \ character |
| \’ | ‘ character |
| \” | ” character |
| \? | ? character |
| \a | Alert or bell |
| \b | Backspace |
| \f | Form feed |
| \n | Newline |
| \r | Carriage return |
| \t | Horizontal tab |
| \v | Vertical tab |
| \xhh . . . | Hexadecimal number of one or more digits |
String Literals
String literals or constants are enclosed in double quotes “” or with @””. A string contains characters that are similar to character literals: plain characters, escape sequences, and universal characters.
You can break a long line into multiple lines using string literals and separating the parts using whitespaces.
Here are some examples of string literals. All the three forms are identical strings.
"hello, world"
"hello, \
world"
"hello, " "w" "orld"
@"c:\windows\documents"Defining Constants
Constants are defined using the const keyword.
Syntax for defining a constant is:
const <data_type> <constant_name> = value;Wrapping out
We have learned about C# constants and literals.
Thank you for reading.
Check for more tutorials at acoptex.lt.
Check for Arduino and Raspberry Pi projects on our website acoptex.com.
Section 1. Introduction. 1.1 C# programming language
Section 1. Introduction. 1.2 Introduction to .NET Framework
Section 1. Introduction. 1.3 C# versions history
Section 1. Introduction. 1.4 C# vs Java
Section 1. Introduction. 1.5 C# get started
Section 1. Introduction. 1.6 Your first program – Hello world
Section 1. Introduction. 1.7 C# identifiers and keywords
Section 2. Fundamentals. 2.1 C# Comments
Section 2. Fundamentals. 2.2 C# Data types
Section 2. Fundamentals. 2.3 C# Constants and Literals
