Compare User Input Text to CSV File C#

Question

If I have user input from a text box in c#, and have a CSV file of words for example with user input being: "Wow that's cool LOL" and the CSV file:

LOL Laughing Out Loud

ROFL Rolling On Floor Laughing

How would I compare the input text to find any matches in the file? How would I load the file?

Answer 1

You can do:

string input = "Wow that's cool LOL";
string[] splitArray = input.Split();
bool ifFound = File.ReadLines("yourCVSFilePath.csv")
                .Any(line => splitArray.Any(line.Contains));

It is doing:

• Split the input into an array of words to be compared individually.
• Loads the file line by line (lazy loading)
• Compare to see if any words in the split array matches any word in the line.

If you want to perform string comparison ignoring case then you can do:

bool ifFound = File.ReadLines("yourCVSFilePath.csv")
                .Any(line => 
                        splitArray.Any(sa => 
                                    line.IndexOf(sa, StringComparison.CurrentCultureIgnoreCase) > -1));

Answer 2

You can use File.ReadLines to read the lines from the csv file and LINQ to filter them:

string input = "Wow that's cool LOL";
string[] words = input.Split();

char delimiter = '\t';  // for example
IEnumerable<string> matchingLines = File.ReadLines("yourCVSFilePath.csv")
    .Where(line => words.Intersect(line.Split(delimiter)).Any())
    .ToList(());

The Intersect ... Any approach is an optimized version of this alternative query:

......
.Where(line => words.Any(word => line.Split(delimiter).Contains(word)))