How to obtain an array which contains every sixth (or nth) word from a string?

Question

I have a string that I have obtained from a text file. This string contains about 1200 words. The words are separated by spaces - sometimes one space, and sometimes more than one space.

How do I make an array that contains every sixth word (or nth word, for that matter).

Split on spaces then maybe something like this: http://stackoverflow.com/questions/682615/how-can-i-get-every-nth-item-from-a-listt — lintmouse, Aug 14 '15 at 14:28

score 13 · Answer 1 · edited Aug 15 '15 at 03:16

13

Do a split and then filter by index of the word:

text.Split(new char[]{' '}, StringSplitOptions.RemoveEmptyEntries)
    .Where((word, index) => index % 6 == 0)
    .ToArray()

edited Aug 15 '15 at 03:16

Artiom

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answered Aug 14 '15 at 14:28

Andrei

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yeah, this one looks nicer. Didn't know where has index option – Artiom Aug 14 '15 at 14:29
Yeah, the `Where` has the index. Your solution is better Andrei, since you also include the split which I overlooked in my answer – samy Aug 14 '15 at 14:32

Artiom · Answer 2 · 2015-08-14T14:43:59.453

3

private string[] GetWords(string path, int step){
    var words = File.ReadAllText(path).Split(new []{' '}, StringSplitOptions.RemoveEmptyEntries);
    var resultList = new List<string>(words.Length/step);
    for(var i=0; i<words.Length; i+=step)
    {
       var word = words[i];
       resultList.Add(word);
    }
    return resultList.ToArray();
}

edited Aug 14 '15 at 14:43

answered Aug 14 '15 at 14:28

Artiom

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though seems less elegant then using linq, this will also work, and might proove usefull when working with older .net versions – Zohar Peled Aug 14 '15 at 14:30
@akalikin my fault. Thanks. – Artiom Aug 14 '15 at 14:34
Error 2 The name 'GetTextFromFile' does not exist in the current context. – Henrik Torgersen Aug 14 '15 at 14:34
@HenrikTorgersen fixed – Artiom Aug 14 '15 at 14:35
Error 2 The best overloaded method match for 'string.Split(params char[])' has some invalid arguments Error 3 Argument 2: cannot convert from 'System.StringSplitOptions' to 'char' – Henrik Torgersen Aug 14 '15 at 14:41
@HenrikTorgersen thanks. Split method accepts char array as first parameter. Fixed. – Artiom Aug 14 '15 at 14:44
@HenrikTorgersen anyway I would suggest to go with Andrei solution. it's far shorter and more readable. So accept his answer. – Artiom Aug 14 '15 at 14:57

score 0 · Answer 3 · answered Aug 14 '15 at 14:30

Simply take all words where index is mod N in your list with a Where linq query:

var words = new List<string> {"word1", "word2", "word3", "word4", "word5", "word6"};
var n = 2;
var nthWords = words.Where((word, index) => (index % n) == 0).ToArray();

nthWords now contains word1 word3 word5

How to obtain an array which contains every sixth (or nth) word from a string?

3 Answers3