Checking if string contains multiple letters

Question

I have a collection of an object called dictionaryWords.

For each word in this collection I need to check if it does not contain certain letters. If it does contain one or more of a certain letter it is removed from the collection.

Example:

Collection before removal: ['abc','dee',fff']
letters to check for: e,f
Collection after removal: ['abc']

Rather than specifying multiple letters is there a way to check against an array?

My code:

foreach(DictionaryWord word in dictionaryWords)
{
    if (!word.Contains("D") && !word.Contains("E") // optimize this line
    {
        // Word does not contain letters, word is good
    }
}

How can I replace the "optimize this line" to say "if word contains any letter from an array of values"

Thanks, Andrew

Felipe Oriani · Accepted Answer · 2014-02-11 16:02:09Z

3

Try something like this:

// isolate the letters
string[] letters = new string[] { "D", "E", "F" }; // other strings or letters

// interate between your data
foreach(DictionaryWord word in dictionaryWords)
{
    // check if the work does not contain any letter
    if (!letters.Any(x => word.Contains(x))
    {
        // Word does not contain letters, word is good
    }
}

answered Feb 11, 2014 at 16:02

Felipe Oriani

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Comments

JaredPar · Accepted Answer · 2014-02-11 16:03:42Z

1

Why not abstract this out to a function?

void CheckForLetters(IEnumerable<DictionaryWord> source, IEnumerable<char> letters) {
  foreach (var word in source) { 
    if (letters.any(c => word.Contains(c)) { 
      // It has the letter
    }
  }
}

answered Feb 11, 2014 at 16:03

JaredPar

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Comments

bblincoe · Accepted Answer · 2014-02-11 16:03:12Z

0

Create a method that accepts an array of characters to compare against.

The prototype would look like the following: bool isLetterInWord(DictionaryWord word, char[] letters);

answered Feb 11, 2014 at 16:03

bblincoe

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Comments

Markus · Accepted Answer · 2014-02-11 16:12:53Z

0

Assuming that you can map your DictionaryWord class to a string, you can use a Linq query for this:

var words = new string[] { "abc", "def", "fe" };
var lettersToExclude = new char[] { 'e', 'f' };
var goodWords = from x in words where !lettersToExclude.Intersect(x).Any() select x;

edited Feb 11, 2014 at 16:12

answered Feb 11, 2014 at 16:06

Markus

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Comments

Jimmy · Accepted Answer · 2014-02-11 16:18:59Z

0

Use HashSets and make use of IsSubsetOf method

http://msdn.microsoft.com/en-us/library/bb358446(v=vs.110).aspx

 string str = "teststing";

 var strset = new HashSet<char>(str.ToCharArray());
 var charstoCheck = new HashSet<char>(new Char[] {'z'});
 bool isstrcontainschars = charstoCheck.IsSubsetOf(strset);

edited Feb 11, 2014 at 16:18

answered Feb 11, 2014 at 16:08

Jimmy

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Comments

Guilherme Oliveira · Accepted Answer · 2014-02-11 16:25:14Z

0

You could use Regex for that.

string value = "abcdef";
var result = new Regex("[d-e-f]").Replace(value, string.Empty);

It checks if the string contains the letters at the Regex's constructor, and replace the letters for what you want. In my example, I replaced the letter to string.Empty.

In your case, you could do like this:

if (new Regex("[d-e-f]").IsMatch(word))
{
    //Do something.
}

edited Feb 11, 2014 at 16:25

answered Feb 11, 2014 at 16:16

Guilherme Oliveira

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