Technical Test No.2 On C# (Paper with Quation And Answer)

               Technical Test Paper 2

             (File system,collection,Generic,Treading) 

  Q . 1) In which collection is the Input / Output based on key?
   Ans:-    HashTable
                SortedList

 Q. 2)In a HashTable key can not be NULL,but Value can be.
   Ans:-  True

 Q. 3) Which of The following statements are correct about the C#.NET code snippet given ?
     Stack s=new Stack();
                   s.Push("Hello");
                   s.Push(8.2);
                   s.Push(5);
                   s.Push('b');
                   s.Push(true);

 Ans:-  This is perfectly workable code.

 Q. 4) A HashTable t maintains a collection of names of states and capital city of each state.Which  is correct way to find out
wheatther " Kerla '' state is present in this collection or not?

Ans:- t.ContainsKey("Kerla");

Q. 5) Suppose value of the Capacity property of ArrayList Collection is set to 4.What will be the capacity  of the collection on adding fifth element  to it?

Ans:- 8

Q. 6) Which of the following statement are correct about Collection Classes  available in network class  library

Ans:-They use efficient algorithms to manage the collection,thereby improving the performance of the  program.

Q. 7) What is advantages of generics?

Ans:- Generic Provide type safety without the overhead of multiple imlementation.

Q.8) Which are the classes are present in system.Collection.Generic namespaces?
Ans:-   Stack
           SortedDictionary

Q. 9) Trace the output

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;

namespace ConsoleApplication4
{
    class Program
    {
        public static void CallToChildThread()
        {
            Console.WriteLine(" child thread starts");
            int sleepfor = 5000;
            Console.WriteLine("Child thread paused for {0} seconds",sleepfor/1000);
            Thread.Sleep(5000);
            Console.WriteLine("child thread resumes");
        }

        static void Main(String[] args)
        {
            ThreadStart childref = new ThreadStart(CallToChildThread );
            Console.WriteLine("In main: creating the child thread");
            Thread childthread = new Thread(childref );
            childthread.Start();
            Console.ReadKey();
        }
    }
}

Ans:-o/p:-
            In main: creating the child thread
            child thread starts
            Child thread paused for 5 seconds
            child thread resumes
 

Q.10) Explain Thread LifeCycle .
Ans:------
    

A thread is defined as the execution path of a program. Each thread defines a unique flow of control. If your application involves complicated and time consuming operations then it is often helpful to set different execution paths or threads, with each thread performing a particular job.

Threads are lightweight processes. One common example of use of thread is implementation of concurrent programming by modern operating systems. Use of threads saves wastage of CPU cycle and increase efficiency of an application.

So far we have written programs where a single thread runs as a single process which is the running instance of the application. However, this way the application can perform one job at a time. To make it execute more than one task at a time, it could be divided into smaller threads.

 The life cycle of a thread starts when an object of the System.Threading.Thread class is created and ends when the thread is terminated or completes execution.

Following are the various states in the life cycle of a thread:

• The Unstarted State: it is the situation when the instance of the thread is created but the Start method has not been called.
• The Ready State: it is the situation when the thread is ready to run and waiting CPU cycle.
• The Not Runnable State: a thread is not runnable, when:
  • Sleep method has been called
  • Wait method has been called
  • Blocked by I/O operations
• The Dead State: it is the situation when the thread has completed execution or has been aborted.

11. Discuss File System in Detail.

ANS :
FileStream typical use
This is typical code when opening file using FileStream. It's important to always close the stream. If you don't close the stream it can take a minute to be file again accessible (it will wait to garbage collector to free the FileStream instance and close the file).

[C#] Open existing file for read and write.
FileStream fileStream = new FileStream(@"c:\file.txt", FileMode.Open);

[C#] Open existing file for reading.
FileStream fileStream = new FileStream(@"c:\file.txt", FileMode.Open, FileAccess.Read);

[C#] Open existing file for writing.
FileStream fileStream = new FileStream(@"c:\file.txt", FileMode.Open, FileAccess.Write);

[C#] Open file for writing (with seek to end), if the file doesn't exist create it.
FileStream fileStream = new FileStream(@"c:\file.txt", FileMode.Append);

[C#] Create new file and open it for read and write, if the file exists overwrite it.
FileStream fileStream = new FileStream(@"c:\file.txt", FileMode.Create);

[C#] Create new file and open it for read and write, if the file exists throw exception.
FileStream fileStream = new FileStream(@"c:\file.txt", FileMode.CreateNew);
Example;
         

using System;
using System.IO;

class Test
{
    public static void Main()
    {
        string path = @"c:\temp\MyTest.txt";
        if (!File.Exists(path))
        {
            // Create a file to write to.
            using (StreamWriter sw = File.CreateText(path))
            {
                sw.WriteLine("Hello");
                sw.WriteLine("And");
                sw.WriteLine("Welcome");
            }
        }

        // Open the file to read from.
        using (StreamReader sr = File.OpenText(path))
        {
            string s = "";
            while ((s = sr.ReadLine()) != null)
            {
                Console.WriteLine(s);
            }
        }
    }
}