Modify list of strings to only have max n-length strings (use of Linq)

Question

Suppose we have a list of strings like below:

List<string> myList = new List<string>(){"one", "two", "three", "four"};

There are some items with the length of more than 3.

By the help of Linq I want to divide them into new items in the list, so the new list will have these items:

{"one", "two", "thr", "ee", "fou", "r"};

Don't ask me why Linq. I am a Linq fan and don't like unLinq code :D

Answer 1

For real code basic for would likely be better (i.e. as shown in other answer.

If you really need LINQ split string into 3-letter chunks and than merge all with SelectMany:

var list = new[]{"", "a", "abc","dee","eff","aa","rewqs"};
var result = list
  .Select( 
    s => 
      Enumerable.Range(0, s.Length / 3 + 
             (s.Length == 0 || (s.Length % 3 > 0) ? 1 : 0))
      .Select(i => s.Substring(
         i * 3,
         Math.Min(s.Length - i * 3, 3))))
  .SelectMany(x=>x);

Range creates enumerable for all segments of the string (which is either length/3 if all pieces are exactly 3 characters, or one more if last one is shorter than 3 character).

.Select(i => s.Substring... splits string into chunks of 3 or less characters (need to carefully adjust length to avoid index out of range error)

.SelectMany combines list of list of 3 character segments into flat list of 3 character segments.

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Note: This LINQ code should be used for entertainment/learning purposes. If you must use similar LINQ solution in production code at least convert splitting of string into more readable helper function.

Answer 2

I'm not sure you can do that with Linq. Here is a non-linq solution:

for (int x = 0; x < myList.Count; x++)
{
    if (myList[x].Length > 3)
    {
        var oldString = myList[x];
        myList[x] = oldString.Substring(0, 3);
        myList.Insert(x + 1, oldString.Substring(3));
    }
}

Edit: Apparently you can do that with Linq. Well, this is a non-linq solution anyways...