C# Interview Questions and Answers (958) - Page 16

Use the Repeat function of Enumerable class.

Enumerable class belongs to System.Linq namespace

int[] b = Enumerable.Repeat(45, 5).ToArray();

45: initial value

5: number of times the initial value should repeat.
foreach (var z in b)
{
Console.WriteLine(z);
}

NOTE: This is objective type question, Please click question title for correct answer.

The Value Types which includes most built-in types such as numeric types, char types and bool types as well as the custom struct and enum types. The content of a Value Type variable is simply a value.

But in case of Reference Types, it includes all classes, array, interface, and delegate types. This is quite different from value type. It contains two parts that is an object and the reference to that object. The content of this type is a reference to an object that contains a value.

The basic difference between them is, how they are handled inside the memory.

var:
1)It is a keyword that is used for implicit variable declaration
ex: var a=100;
var b="welcome";
The compiler determines the datatype of the variable declared with var keyword
on the basis of assigned value. we have to assign value with variable declaration
ex: var a;
a="welcome"; This is wrong


2)var cannot be used to declare variables at class level.
3)var cannot be used as the return type of methods.
4)Intoduced in c# 3.0

dynamic:
1)It is a keyword used for variable declaration

ex: dynamic a=100;

dynamic b;
b="good";

The datatype of the variable is determined at runtime

2)dynamic can also be used to declare class level variables

ex: class aa
{
dynamic d; //correct

}

3)dynamic can also be used as return type of the methods

example:

class dd
{
static dynamic pp()
{
dyanmic d;
d=<some value>;
return d;
}
}

4)Introduced in c# 4.0

Hi All

We can prove this by using Object.GetHashCode () Method provided in super class of all .net langues..

The hash code is a numeric value that is used to identify an object..

Please refer the below line of code..

using System;

using System.Text;



  class Program

    {

        static void Main(string[] args)

        {

            string strtemp ="Prad";

            Console.WriteLine(strtemp +"            "+ strtemp.GetHashCode());



            strtemp = strtemp + "eep";

            Console.WriteLine(strtemp +"      "+strtemp.GetHashCode());



            StringBuilder sb = new StringBuilder("Prad");

            Console.WriteLine(sb + "            " + sb.GetHashCode());



            sb.Append("eep");

            Console.WriteLine(sb + "      " + sb.GetHashCode());

        }

    }



/*output 

Prad      432992021

Pradeep  -673750172

Prad      46104728

Pradeep   46104728 */

As we can see for any operation performed on the string the new memory is created that y it is called immutable..

while for stringbuilder for all the operation the same memory is being modified.. as we can see the hashcode both time is same.

Happy coding :-)

NOTE: This is objective type question, Please click question title for correct answer.

NOTE: This is objective type question, Please click question title for correct answer.

Example:

if there is a filename known as aa.txt in C drive and we want to change its name

to bb.txt.

Use this code snippet:

File.Move("c:\\aa.txt","c:\\bb.txt");

You must include the namespace System.IO

Yes, we can change both the dimensions of this array dynamically.
Code:

        int[,] arr = new int[4, 5];

                Console.WriteLine(arr.GetLength(0) + "---" + arr.GetLength(1));

                int b = 6;

                arr = new int[b, b];

                Console.WriteLine(arr.GetLength(0) + "---" + arr.GetLength(1));

When you run the program, the Getlengthmethod will show different number of dimensions.

It can be 0 to as many.
try must be followed by catch or finally.

ex:
1)0 catch statement
try
{

}
finally
{

}


2) any number
try
{

}

catch
{

}
catch
{

}
finally
{

}