Basic types

This topic lists the basic types that are defined in F#. These types are the most fundamental in F#, forming the basis of nearly every F# program. They are a superset of .NET primitive types.

Type	.NET type	Description	Example
bool	Boolean	Possible values are true and false.	true/false
byte	Byte	Values from 0 to 255.	1uy
sbyte	SByte	Values from -128 to 127.	1y
int16	Int16	Values from -32768 to 32767.	1s
uint16	UInt16	Values from 0 to 65535.	1us
int	Int32	Values from -2,147,483,648 to 2,147,483,647.	1
uint	UInt32	Values from 0 to 4,294,967,295.	1u
int64	Int64	Values from -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807.	1L
uint64	UInt64	Values from 0 to 18,446,744,073,709,551,615.	1UL
nativeint	IntPtr	A native pointer as a signed integer.	nativeint 1
unativeint	UIntPtr	A native pointer as an unsigned integer.	unativeint 1
decimal	Decimal	A floating point data type that has at least 28 significant digits.	1.0m
float, double	Double	A 64-bit floating point type.	1.0
float32, single	Single	A 32-bit floating point type.	1.0f
char	Char	Unicode character values.	'c'
string	String	Unicode text.	"str"
unit	not applicable	Indicates the absence of an actual value. The type has only one formal value, which is denoted (). The unit value, (), is often used as a placeholder where a value is needed but no real value is available or makes sense.	()

Note

You can perform computations with integers too big for the 64-bit integer type by using the bigint type. bigint is not considered a basic type; it is an abbreviation for System.Numerics.BigInteger.

See also

• F# Language Reference