ValueTypeReference types add indirection. They point to another memory location. Value types do not—they are self-contained, often in the bytes on the evaluation stack.
Value types are used constantly in C# programs. Even a simple for-loop uses an int value type to iterate. All values are considered structs.
This program shows an int value type. Int is stored entirely within stack memory space. The managed heap is not touched—no allocation occurs there.
int, that memory location's value is changed. No new int is created as a result of the addition.using System;
class Program
{
static void Main()
{
int value = 10;
value += DateTime.Today.Day;
Console.WriteLine(value);
}
}15ClassThe ValueType class is a base class for all value types. This includes ints, shorts, doubles, and also structs such as DateTime instances.
ValueType to refer to these values, and also as a parameter type in methods.ValueType is a class, which means it is not a value type itself. It is just a representation of a value type.class for values, you can refer to those values through a ValueType reference variable.using System;
class Program
{
static ValueType _valueType = false;
static void Main()
{
// You can refer to System.Int32 as a ValueType.
ValueType type1 = 5;
Console.WriteLine(type1.GetType());
// You can refer to System.DateTime as a ValueType.
ValueType type2 = DateTime.Now;
Console.WriteLine(type2.GetType());
// You can refer to System.Boolean as a ValueType.
Console.WriteLine(_valueType.GetType());
// Pass as parameter.
Method(long.MaxValue);
Method(short.MaxValue);
}
static void Method(ValueType type)
{
Console.WriteLine(type.GetType());
}
}System.Int32
System.DateTime
System.Boolean
System.Int64
System.Int16A ValueType parameter a way to require that an argument is a value type. This is an additional constraint over an object parameter.
class for all types. In this way it is similar to ValueType, but ValueType too is a subclass of object.classThe ValueType class may be useful in some programs. It is important as a base class for actual value types. This is why it has no constructor.
int, long, short, DateTime) and not bother with ValueType itself.A blittable type is compatible to an unmanaged type. Programs that use blittable types do not need to convert them before passing them to an unmanaged DLL.
byte boolean.byte) character.A variable stores a value. In programs, even a reference (pointer) is a value. It is simply a value that points to another value. The ValueType class is an important detail.