C#: Read a specific line from a file

C# Sharp File Handling: Exercise-13 with Solution

Write a program in C# Sharp to read a specific line from a file.

Sample Solution:-

C# Sharp Code:

using System; // Importing the System namespace for basic functionalities
using System.IO; // Importing the System.IO namespace for file operations

class filexercise13 // Declaring a class named filexercise13
{
    static void Main() // Declaring the Main method
    {
        string fileName = @"mytest.txt"; // Initializing a string variable with the file name
        string[] ArrLines; // Declaring an array to store lines of text
        int n, i, l; // Declaring variables for iteration, line count, and specific line to read

        // Displaying a message to read a specific line from a file
        Console.Write("\n\n Read a specific line from a file  :\n");
        Console.Write("----------------------------------------\n");

        if (File.Exists(fileName)) // Checking if the file exists and deleting it if true
        {
            File.Delete(fileName); // Deleting the file if it exists
        }

        Console.Write(" Input number of lines to write in the file  :");
        n = Convert.ToInt32(Console.ReadLine()); // Reading user input for the number of lines
        ArrLines = new string[n]; // Initializing the array to store lines

        Console.Write(" Input {0} strings below :\n", n); // Prompting user to input lines
        for (i = 0; i < n; i++)
        {
            Console.Write(" Input line {0} : ", i + 1);
            ArrLines[i] = Console.ReadLine(); // Reading lines of text from user input
        }

        // Writing all lines to the file
        System.IO.File.WriteAllLines(fileName, ArrLines);

        Console.Write("\n Input which line you want to display  :");
        l = Convert.ToInt32(Console.ReadLine()); // Reading user input for the line number to display

        if (l >= 1 && l <= n) // Checking if the specified line number is within the valid range
        {
            Console.Write("\n The content of the line {0} of the file {1} is : \n", l, fileName);
            if (File.Exists(fileName)) // Checking if the file exists
            {
                string[] lines = File.ReadAllLines(fileName); // Reading all lines from the file
                Console.WriteLine(" {0}", lines[l - 1]); // Writing the specific line to the console
            }
        }
        else
        {
            Console.WriteLine(" Please input the correct line number."); // Displaying message for incorrect line number
        }
        Console.WriteLine();
    }
}

Sample Output:

 Read a specific line from a file  :                                                                          
----------------------------------------                                                                      
 Input number of lines to write in the file  :2                                                               
 Input 2 strings below :                                                                                      
 Input line 1 : welcome w3resource                                                                            
 Input line 2 : this is a tutorial                                                                            
   
 Input which line you want to display  :1                                                                     
     
 The content of the line 1 of the file mytest.txt is :                                                        
 welcome w3resource

Flowchart :

C# Sharp Code Editor:

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