CODEWITHSUNDEEP
c#stringienumerable
Ehsan Akbar
Ehsan Akbar

Reputation: 7301

Remove an item from ienumerable<string>

I have a method that expect IEnumerable<string> as you can see here :

  public static string FromDecimalAscii(IEnumerable<string> input)
        {

            return new string(input.Select(s => (char)int.Parse(s)).ToArray());
        }

But every time the last record of my IEnumerable is empty so i got an error in this line because of that :

    return new string(input.Select(s => (char)int.Parse(s)).ToArray());

So i have to remove that item from my IEnumerable .

The error:Input string was not in a correct format Any ideas will be appreciated.

Best regards

Upvotes: 0

Views: 579

Answers (1)

user2160375
user2160375

Reputation:

You need just to filter collection with Where:

return new string(input.Where(s => !string.IsNullOrEmpty(s))
                       .Select(s => (char)int.Parse(s)).ToArray());

You can also use extension method to use TryParse:

static class Extensions
{
    public delegate bool TryParseDelegate<TSource>(string s, out TSource source);

    public static IEnumerable<TResult> WhereParsed<TSource, TResult>(
                                               this IEnumerable<TSource> source,
                                               TryParseDelegate<TResult> tryParse)
    {

         // TODO: check arguments against null first

        foreach (var item in source)
        {
            TResult result;
            if (tryParse(item != null ? item.ToString() : null, out result))
            {
                yield return result;
            }
        }
    }
}

Usage:

var collection = input.WhereParsed<string, int>(int.TryParse)
                      .Cast<char>()
                      .ToArray();
return new string(collection);

Upvotes: 6

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