Last Updated : 15 Jan, 2025
Data types specify the type of data that a valid C# variable can hold. C# is a strongly typed programming language because in C# each type of data (such as integer, character, float, and so forth) is predefined as part of the programming language and all constants or variables defined for a given program must be described with one of the data types.
Data Types in C# is Mainly Divided into 3 Categories:
In C#, the Value Data Types will directly store the variable value in memory and it will also accept both signed and unsigned literals. The derived class for these data types are System.ValueType. Following are different Value Data Types in C# programming language
1.1 Signed & Unsigned Integral TypesThere are 8 integral types which provide support for 8-bit, 16-bit, 32-bit, and 64-bit values in signed or unsigned form.
Alias Type Name Type Size(bits) Range Default Value sbyte System.Sbyte signed integer 8 -128 to 127 0 short System.Int16 signed integer 16 -32768 to 32767 0 Int System.Int32 signed integer 32 -231 to 231-1 0 long System.Int64 signed integer 64 -263 to 263-1 0L byte System.byte unsigned integer 8 0 to 255 0 ushort System.UInt16 unsigned integer 16 0 to 65535 0 uint System.UInt32 unsigned integer 32 0 to 232 0 ulong System.UInt64 unsigned integer 64 0 to 263 0 1.2 Floating Point TypesThere are 2 floating point data types which contain the decimal point.
Alias Type name Size(bits) Range (aprox) Default Value float System.Single 32 ±1.5 × 10-45 to ±3.4 × 1038 0.0F double System.Double 64 ±5.0 × 10-324 to ±1.7 × 10308 0.0DThe decimal type is a 128-bit data type suitable for financial and monetary calculations. It has 28-29 digit Precision. To initialize a decimal variable, use the suffix m or M. Like as, decimal x = 300.5m;. If the suffix m or M will not use then it is treated as double.
Alias Type name Size(bits) Range (aprox) Default value decimal System.Decimal 128 ±1.0 × 10-28 to ±7.9228 × 1028 0.0M 1.4 Character TypesThe character types represents a UTF-16 code unit or represents the 16-bit Unicode character.
Alias Type name Size In(Bits) Range Default value char System.Char 16 U +0000 to U +ffff '\0'Example 1:
C#
// C# program to demonstrate
// the above data types
using System;
namespace ValueTypeTest {
class GeeksforGeeks {
// Main function
static void Main()
{
// declaring character
char a = 'G';
// Integer data type is generally
// used for numeric values
int i = 89;
short s = 56;
// this will give error as number
// is larger than short range
// short s1 = 87878787878;
// long uses Integer values which
// may signed or unsigned
long l = 4564;
// UInt data type is generally
// used for unsigned integer values
uint ui = 95;
ushort us = 76;
// this will give error as number is
// larger than short range
// ulong data type is generally
// used for unsigned integer values
ulong ul = 3624573;
// by default fraction value
// is double in C#
double d = 8.358674532;
// for float use 'f' as suffix
float f = 3.7330645f;
// for float use 'm' as suffix
decimal dec = 389.5m;
Console.WriteLine("char: " + a);
Console.WriteLine("integer: " + i);
Console.WriteLine("short: " + s);
Console.WriteLine("long: " + l);
Console.WriteLine("float: " + f);
Console.WriteLine("double: " + d);
Console.WriteLine("decimal: " + dec);
Console.WriteLine("Unsinged integer: " + ui);
Console.WriteLine("Unsinged short: " + us);
Console.WriteLine("Unsinged long: " + ul);
}
}
}
char: G integer: 89 short: 56 long: 4564 float: 3.733064 double: 8.358674532 decimal: 389.5 Unsinged integer: 95 Unsinged short: 76 Unsinged long: 3624573Example 2: C#
// Sbyte signed integral data type
using System;
namespace ValueTypeTest {
class GeeksforGeeks {
// Main function
static void Main()
{
sbyte a = 126;
// sbyte is 8 bit
// singned value
Console.WriteLine(a);
a++;
Console.WriteLine(a);
// It overflows here because
// byte can hold values
// from -128 to 127
a++;
Console.WriteLine(a);
// Looping back within
// the range
a++;
Console.WriteLine(a);
}
}
}
Example 3:
C#
// C# program to demonstrate
// the byte data type
using System;
namespace ValueTypeTest {
class GeeksforGeeks {
// Main function
static void Main()
{
byte a = 0;
// byte is 8 bit
// unsigned value
Console.WriteLine(a);
a++;
Console.WriteLine(a);
a = 254;
// It overflows here because
// byte can hold values from
// 0 to 255
a++;
Console.WriteLine(a);
// Looping back within the range
a++;
Console.WriteLine(a);
}
}
}
1.5 Boolean Types
It has to be assigned either true or false value. Values of type bool are not converted implicitly or explicitly (with casts) to any other type. But the programmer can easily write conversion code.
Alias
Type Name
Possible Values
bool
System.Boolean
true / false
Example:
// Using Boolean data type
using System;
namespace ValueTypeTest {
class GeeksforGeeks {
// Main function
static void Main()
{
// boolean data type
bool b = true;
if (b == true)
Console.WriteLine("Hi Geek");
}
}
}
2. Reference Data Types
The Reference Data Types will contain a memory address of variable value because the reference types won’t store the variable value directly in memory. When you create a reference type variable, such as an object or a string, you are actually storing a reference (or pointer) to the location in memory where the data is held. The actual data for reference types is stored on the heap. The heap is a large pool of memory used for dynamic memory allocation. The built-in reference types are string, object.
2.1 StringIt represents a sequence of Unicode characters and its type name is System.String. So, string and String are equivalent.
Example:
string s1 = "hello"; // creating through string keyword2.2 Object
String s2 = "welcome"; // creating through String class
In C#, all types, predefined and user-defined, reference types and value types, inherit directly or indirectly from Object. So basically it is the base class for all the data types in C#. Before assigning values, it needs type conversion. When a variable of a value type is converted to object, it's called boxing. When a variable of type object is converted to a value type, it's called unboxing. Its type name is System.Object.
Example:
C#
// Using Reference data types
using System;
namespace ValueTypeTest {
class Geeks {
// Main Function
static void Main()
{
// declaring string
string a = "Geeks";
// append in a
a += "for";
a = a + "Geeks";
Console.WriteLine(a);
// declare object obj
object obj;
obj = 20;
Console.WriteLine(obj);
// to show type of object
// using GetType()
Console.WriteLine(obj.GetType());
}
}
}
GeeksforGeeks 20 System.Int323. Pointer Data Type
The Pointer Data Types will contain a memory address of the variable value. To get the pointer details we have a two symbols ampersand (&) and asterisk (*).
Syntax:
type* identifier;
Example:
// Valid syntax
int* p1, p;
// Invalid
int *p1, *p;
Note: This program will not work on online compiler Error: Unsafe code requires the `unsafe' command line option to be specified. For its solution: Go to your project properties page and check under Build the checkbox Allow unsafe code.
Implementation:
C#
// Using Pointer Data Type
using System;
namespace Pointerprogram {
class GFG {
// Main function
static void Main()
{
unsafe
{
// declare variable
int n = 10;
// store variable n address
// location in pointer variable p
int* p = &n;
Console.WriteLine("Value :{0}", n);
Console.WriteLine("Address :{0}", (int)p);
}
}
}
}
Output:
Value :10
Address :1988374520
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