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what is the difference between value type and reference type?

Posted By :BangaruBabuPureti     Posted Date :June 23, 2010    Points :10   Category :Sql Server 
Value type is stored in stack.
Reference type stored in heap.

You can also find related Interview Question to what is the difference between value type and reference type?  below: 

Value type & reference types difference? Example from .NET. Integer & struct are value types or reference types in .NET?

Most programming languages provide builtin data types, such as integers and floatingpointnumbers, that are copied when they are passed as arguments (that is, they are passed by value). In the .NET Framework, these are called value types. The runtime

supports two kinds of value types:
· Builtin
value types
The .NET Framework defines builtin
value types, such as System.Int32 and
System.Boolean, which correspond and are identical to primitive data types
used by programming languages.
· Userdefined
value types
Your language will provide ways to define your own value types, which derive from System.ValueType. If you want to define a type representing a value that is small, such as a complex number (using two floatingpoint numbers),
you might choose to define it as a value type because you can pass the value type efficiently by value. If the type you are defining would be more efficiently passed by reference, you should define it as a class instead.

Variables of reference types, referred to as objects, store references to the actual data. This following are the reference types:
· class
· interface
· delegate
This following are the builtin
reference types:
· object (More...)

Difference between type constructor and instance constructor? What is static constructor, when it will be fired? And what is its use?

(Class constructor method is also known as type constructor or type initializer)
Instance constructor is executed when a new instance of type is created and the class constructor is executed after the type is loaded and before any one of the type members is accessed. (It will get executed only 1st time, when we call any static methods/fields in the same class.) Class constructors are used for static field initialization. Only one class constructor per type is permitted, and it cannot use the vararg (variable argument) calling convention. (More...)

How do I call a member method and pass a primitive type (Value Type) by reference?

Use the ref keyword when declaring the parameter of the method, for example:

public bool GetValue( ref int returnValue );

This will pass the numeric by reference.You can modify the value of returnValue within the body of GetValue and it will persist when the method call returns. (More...)

convert a value-type to a reference type is known as?


Boxing is the terminology used in .NET Framework to convert Value type to reference type (More...)

convert a Reference Type to a Value type is known as?


UnBoxing is the terminology used in .NET Framework to convert Reference Type to a Value type (More...)

Is array reference type / value type?

Array is a reference type and it is stored in Heap memory!

Reference types are:


Is string reference type / value type?

string is reference type
because String is immutable objects..........
means does not change the values(string)....... (More...)

What is Reference type and value type ?

Reference Type:
Reference types are allocated on the managed CLR heap, just like object types.
A data type that is stored as a reference to the value's location. The value of a reference type is the location of the sequence of bits
that represent the type's data. Reference types can be self-describing types, pointer types, or interface types

Value Type:
Value types are allocated on the stack just like primitive types in VBScript, VB6 and C/C++. Value types are not instantiated using new go out of scope when the function they are defined within returns.
Value types in the CLR are defined as types that derive from system.valueType.

A data type that fully describes a value by specifying the sequence of bits that constitutes the value's representation. Type information for a value type instance is not stored with the instance at run time, but it is available in metadata. Value type instances can be treated as objects using boxing.

Explain Value type and reference type?

Value Type
Variables of value types directly contain their data.
Value types store in stack.
Reference Type
Variables of reference types store references to their data
Reference types store in Heap Memory.


How do you call a Member method and pass a value Type by reference?

use the "ref" keyword when declaring a Parameter of the Method
public bool GetValue(ref int returnvalue);

An Interface is a Value type or reference Type?

Interface is a Value type as well as Reference type (More...)

How do you call a Member method and pass a value Type by reference?

use the "ref" keyword when declaring a Parameter of the Method (More...)

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