Question

I have a string that needs to be chopped up. I’d like to do this in LINQ.
The string can have up to 32 letters.
I’d like to collect the parts in a dictionary.

The 1st part needs to have the first 4 letters. 
The 2nd part needs to have the first 5 letters. 
The 3rd part needs to have the first 6 letters. 
etc.

The key of the dictionary is simply a counter. I don’t know the length of the string, the min. length is 4.
How would I do this createively in LINQ?

Answer 1

You could make it an extension:

public static Dictionary<int, String> Chop(this string str, int minLength)
{
    if (str == null) throw new ArgumentException("str");
    if (str.Length < minLength) throw new ArgumentException("Length of string less than minLength", "minLength");
    var dict = str.TakeWhile((c, index) => index <= str.Length - minLength)
        .Select((c, index) => new { 
            Index = index, 
            Value = str.Substring(0, minLength + index) 
        }).ToDictionary(obj => obj.Index, obj => obj.Value);

    return dict;
}

Call it in this way:

Dictionary<int, String> = "Insert sample string here".Chop(4);