Difference between object and instance in c#?

Aditya Kumar

9y1.3kLearn iOS Programming

I am confused with such these topics.

What is diffrence between variable and refrence variable?

What is diffrence between object and instance?

What is refrence pointer?

Thanks alot.

3 Replies

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Nilesh Jadav9y ago
Accepted answer
Variable -> In programming, a variable is a value that can change, depending on conditions or on information passed to the program. Typically, a program consists of instruction s that tell the computer what to do and data that the program uses when it is running. The data consists of constants or fixed values that never change and variable values (which are usually initialized to "0" or some default value because the actual values will be supplied by a program's user). Usually, both constants and variables are defined as certain data types.

Refrence Variable -> A reference variable is an alias, that is, another name for an already existing variable. Once a reference is initialized with a variable, either the variable name or the reference name may be used to refer to the variable.
#include

using namespace std;

int main () {
   // declare simple variables
   int    i;
   double d;

   // declare reference variables
   int&    r = i;
   double& s = d;

   i = 5;
   cout << "Value of i : " << i << endl;
   cout << "Value of i reference : " << r  << endl;

   d = 11.7;
   cout << "Value of d : " << d << endl;
   cout << "Value of d reference : " << s  << endl;

   return 0;
}

OUTPUT:

Value of i : 5
Value of i reference : 5
Value of d : 11.7
Value of d reference : 11.7
Refrence Variable :

Student st;

Now if you wanted to create an instance or object of the Student class, you would do so:

Create an reference and an object

Student st = new Student();
The basic concept of OOP is this: Class >> Object >> Instance.

The class = the blue print. The Object is an actual thing that is built based on the 'blue print' (like the house). An instance is a virtual copy (but not a real copy) of the object.
Refer this : http://stackoverflow.com/questions/3323330/difference-between-object-and-instance

For Reference pointers :

https://www3.ntu.edu.sg/home/ehchua/programming/cpp/cp4_PointerReference.html

Hope that helps
+1
Khaja Moizuddin9y ago
Variable is nothing but a storage point , if we want to store values like string , integer , boolean , etc then we define a variable and store in it which can be accessed or changed of value in run time. Say if we want to perform Addition of value based on users acceptance we will do it as Int Number1 = Convert.ToInt32(TextboxNumber.Text); Int Num2= Convert.ToInt32(TextboxNumber2.Text); Here we are accepting the Number from user in the textbox from the UI of the application. Public void CalAddition() { Int Addition= Number1+Num2; } Hence Variable can be used for accessing the value or Changing the values. Reference Variable is nothing but a variable which is pointing an object.In C# we create object of an class as Employee Emp= new Employee(); If Employee class contains Methods like IncrementSal() ,EmpAddress() etc then from the above Employee object , Emp is nothing but an reference variable which is used to access the members if Employee class object Example : Emp.EmpAddress(); Emp.IncrementSal();
+1
Hassan Uddin Mughal9y ago
http://www.c-sharpcorner.com/blogs/the-stack-and-the-heap
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