Searching for a Specific Word in a Text File and Displaying the line its on

Question

I am having trouble attempting to find words in a text file in C#.

I want to find the word that is input into the console then display the entire line that the word

Answer 1

How about something like this:

//We read all the lines from the file
IEnumerable lines = File.ReadAllLines("your_file.txt");

//We read the input from the user
Console.Write("Enter the word to search: ");
string input = Console.ReadLine().Trim();

//We identify the matches. If the input is empty, then we return no matches at all
IEnumerable matches = !String.IsNullOrEmpty(input)
                              ? lines.Where(line => line.IndexOf(input, StringComparison.OrdinalIgnoreCase) >= 0)
                              : Enumerable.Empty();

//If there are matches, we output them. If there are not, we show an informative message
Console.WriteLine(matches.Any()
                  ? String.Format("Matches:\n> {0}", String.Join("\n> ", matches))
                  : "There were no matches");

This approach is simple and easy to read, it uses LINQ and String.IndexOf instead of String.Contains so we can do a case insensitive search.