Round #734

Read all lines from a text file using File.ReadAllLines.

**Reading All Lines from a Text File using File.ReadAllLines** Here's an example of how to read all lines from a text file using `File.ReadAllLines` in C#: ```csharp using System; using System.IO; public class Program { public static void Main() { // Specify the path to the text file string filePath = @"C:\Example\example.txt"; try { // Read all lines from the text file string[] lines = File.ReadAllLines(filePath); // Print each line foreach (string line in lines) { Console.WriteLine(line); } } catch (FileNotFoundException ex) { Console.WriteLine("File not found: " + ex.Message); } catch (Exception ex) { Console.WriteLine("An error occurred: " + ex.Message); } } } ``` **Explanation:** 1. We specify the path to the text file using the `filePath` variable. 2. We use a `try-catch` block to handle any exceptions that may occur when reading the file. 3. Inside the `try` block, we call `File.ReadAllLines` and pass the `filePath` as an argument. This method returns an array of strings, where each string represents a line in the file. 4. We then iterate over the array of lines using a `foreach` loop and print each line to the console. 5. In the `catch` blocks, we handle specific exceptions that may occur, such as `FileNotFoundException` if the file does not exist, and a general `Exception` for any other errors. **Note:** `File.ReadAllLines` reads the entire file into memory, so it may not be suitable for very large files. In such cases, you may want to consider using `File.ReadLines` instead, which returns an `IEnumerable<string>` that can be enumerated lazily.

```csharp using System; using System.IO; public class Program { public static string[] ReadAllLinesFromFile(string filePath) { try { return File.ReadAllLines(filePath); } catch (FileNotFoundException ex) { Console.WriteLine($"The file {filePath} was not found."); throw ex; } catch (UnauthorizedAccessException ex) { Console.WriteLine($"Access to the file {filePath} is denied."); throw ex; } catch (Exception ex) { Console.WriteLine($"An error occurred while reading the file {filePath}: {ex.Message}"); throw ex; } } public static void Main() { string filePath = "example.txt"; string[] lines = ReadAllLinesFromFile(filePath); foreach (string line in lines) { Console.WriteLine(line); } } } ``` This C# code reads all lines from a text file using the `File.ReadAllLines` method. The `ReadAllLinesFromFile` method takes a file path as input and returns an array of strings, where each string represents a line in the file. The code includes error handling to catch potential exceptions that may occur when reading the file, such as `FileNotFoundException` if the file does not exist, `UnauthorizedAccessException` if access to the file is denied, and other exceptions that may occur during file reading. In the `Main` method, an example file path is provided, and the `ReadAllLinesFromFile` method is called to read the lines from the file. The lines are then printed to the console. Note that `File.ReadAllLines` reads the entire file into memory, so it may not be suitable for very large files. In such cases, you may want to consider using a `StreamReader` to read the file line by line.