C# | Literals

The fixed values are called as Literal. Literal is a value which is used by the variables. Values can be either an integer, float or string etc.

// Here 100 is a constant/literal.
int x = 100; 

Literals can be of following types:

• Integer Literals
• Floating-point Literals
• Character Literals
• String Literals
• Null Literals
• Boolean Literals

Integer Literals: A literal of integer type is know as the integer literal. It can be octal, decimal or hexadecimal constant. No prefix is required for the decimal numbers. A suffix can also be used with the integer literals like U or u are used for unsigned numbers while l or L are used for long numbers. By default, every literal is of int type. For Integral data types (byte, short, int, long), we can specify literals in 3 ways:

1. Decimal literals (Base 10) : In this form the allowed digits are 0-9.

   int x = 101;
   

2. Octal literals (Base 8) : In this form the allowed digits are 0-7.

   // The octal number should be prefix with 0.
   int x = 0146; 
   

3. Hexa-decimal literals (Base 16) : In this form the allowed digits are 0-9 and characters are a-f. We can use both uppercase and lowercase characters. As we know that c# is a case-sensitive programming language but here c# is not case-sensitive.

   // The hexa-decimal number should be prefix
   // with 0X or 0x.
   int x = 0X123Face; 
   

Examples:

07778    // invalid: 8 is not an octal digit 
045uu    // invalid: suffix (u) is repeated
456    // valid decimal literal
02453    // valid octal literal 
0x65d    // valid hexadecimal literal 
12356    // valid int literal 
304U    // valid unsigned int literal 
3078L    // valid long literal 
965UL    // valid unsigned long literal 

Program:

101
145
64206

Floating-point Literals: The literal which has an integer part, a decimal point, a fractional part and an exponent part is known as the floating point literal. These can be represented either in decimal form or exponential form.

Examples:

Double d = 3.14145       // Valid
Double d = 312569E-5      // Valid
Double d = 125E             // invalid: Incomplete exponent 
Double d = 784f            // valid
Double d = .e45           // invalid: missing integer or fraction

Program:

Output:

101.23
123.222

Note: By default, every floating-point literal is of double type and hence we can’t assign directly to float variable. But we can specify floating-point literal as float type by suffixed with f or F. We can specify explicitly floating point literal as the double type by suffixed with d or D, of course, this convention is not required.

Character Literals: For character data types we can specify literals in 3 ways:

1. Single quote : We can specify literal to char data type as single character within single quote.

   char ch = 'a';
   

2. Unicode Representation : We can specify char literals in Unicode representation ‘uxxxx’. Here xxxx represents 4 hexadecimal numbers.

   char ch = 'u0061';// Here /u0061 represent a.
   

3. Escape Sequence : Every escape character can be specify as char literals.

   char ch = '
   ';
   

   Escape Sequence	Meaning
   \	character
   ’	‘ character
   ?	? character
   ”	” character
   	Backspace
   a	Alert or Bell
   	New Line
   f	Form Feed
   	Carriage Return
   v	Vertical Tab
   xhh…	Hexadecimal number of one or more digits

Example :

a
a
Hello

Geeks    !

String Literals: Literals which are enclosed in double quotes(“”) or starts with @”” are known as the String literals.

Examples:

String s1 = "Hello Geeks!";

String s2 = @"Hello Geeks!";

Program:

Output:

Hello Geeks!
Hello Geeks!

Boolean Literals: Only two values are allowed for Boolean literals i.e. true and false.

Example:

bool b = true;
bool c = false

Program:

Output:

True
False