Memory allocation using new operator in C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Diagnostics;
using System.IO;
using System.Net;
using System.Net.NetworkInformation;
namespace Test1
{
    class Test
    {
    } 
    class Program
    {
        static void Main(string[] args)
        {
            Test t = null;
            Test t1;
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Diagnostics;
using System.IO;
using System.Net;
using System.Net.NetworkInformation;
namespace Test1
{
    class Test
    {
    } 
    class Program
    {
        static void Main(string[] args)
        {
            Test t = new Test();
        }
    }

}

New operator always does not allocate memory

Yes, what you read just now is correct , let me show an example. Here I have created an array and have used the new operator to allocate memory for 10 elements. The following is my C# code.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Diagnostics;
using System.IO;
using System.Net;
using System.Net.NetworkInformation;
namespace Test1
{
    class Program
    {
        static void Main(string[] args)
        {
            int[] a = new int[10];
        }
    }
}

And here is my IL output.

We can see clearly that no memory allocation has occured in spite of using the new operator. Then when will the memory be allocated? The answer is "when we use it in an array in our program". Actually the .NET code optimizer is very smart when it sees that there is no use of an array in the current program, it simply omits the array from being processed. Is it really? Hmm, are you not believing me? Look at the next screen.

Here is my program in which I have declared an array and just made a little operation on it. As in the following:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Diagnostics;
using System.IO;
using System.Net;
using System.Net.NetworkInformation;
namespace Test1
{
    class Program
    {
        static void Main(string[] args)
        {
            int[] a = new int[10];
            a[0] = 100;
        }
    }
}

And have a look at the IL screen.

We can see the array (array name a) has been created in a local variable creation section.

A very interesting fact of the new operator

The interesting fact of the new operator is, when we use the new operator to create an object (if the .NET code optimizer thinks it is really needed) of a particular data type then the initialization operation is also done with that . How?

Here I have created one integer variable "a" using the new operator (Have you ever found such a mad programmer that creates an integer variable using the new operator?) And without initializing it I want to print it's value.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Diagnostics;
using System.IO;
using System.Net;
using System.Net.NetworkInformation;
namespace Test1
{
    class Program
    {
        static void Main(string[] args)
        {
            int a = new int();
            Console.Write("Local variable a:- "+ a +"\n");
            Console.ReadLine();
        }
    }
}

This is the output screen.

See, we do not set the value 0 to the variable "a" but it's showing the value of the variable "a" is 0. But if we try without using the new operator as in the following:

class Program
{
     static void Main(string[] args)
     {
          int a;
          Console.Write("Local variable a:- "+ a +"\n");
          Console.ReadLine();
     }
}

Hmm. Error. Use of unassigned local variable "a".

So the concept is that when we use the new operator to create memory then the memory is created and by default an appropriate value is set. Here the data type is integer so by default 0 has been assigned here. If your data type is string then it will be bull by default. OK, Sourav! This is the case of pre-defined data types; what about user-defined data types like class?

It's very similar to pre-defined data types. Each and every member will be assigned an appropriate value, as in the following example.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Diagnostics;
using System.IO;
using System.Net;
using System.Net.NetworkInformation;
namespace Test1
{
    class Test
    {
       public Int32 Roll;
       public String name;
    }
    class Program
    {
        static void Main(string[] args)
        {
            int a = new int();
            Console.Write("Local variable a:- "+ a +"\n"); 
            Test t = new Test();
            Console.Write("String class member:- "+  t.name + "\n");
            Console.Write("Integer class member:- " +  t.Roll +"\n");
            Console.ReadLine();
        }
    }
}

Here is the output

The String class member is blank because it's null.

Conclusion: Here I have tried to represent the actual purpose of the new operator with an example and of course in my style. If you people like it then please leave your valuable comments below.