Question

I am trying to transform a string made of words starting with an uppercase letter. I want to separate each word with a space and keep only the first uppercase letter. All other letters should be lowercase.

For example, “TheQuickBrownFox” would become “The quick brown fox”.

Obviously, I could use a simple foreach and build a string by checking each character, but I am trying to do it using LINQ.

Would you know how to solve this elegantly using LINQ?

Thank you for your help.

Answer 1

You can split the words using a regular expression (and little LINQ):

public string SplitAsWords(string original)
{
    var matches = Regex.Matches(original, "[A-Z][a-z]*").Cast<Match>();
    var str = string.Join(" ", matches.Select(match => match.Value));
    str = str[0] + str.Substring(1).ToLower();
    return str;
}

A usage example:

[Test]
public void Example()
{
    string str = SplitAsWords("TheQuickBrownFox");
    Assert.That(str, Is.EqualTo("The quick brown fox"));
}

An alternative implementation using regular expression can be (with no LINQ):

public string SplitAsWords(string original)
{
    var str = Regex.Replace(original, "[a-z][A-Z]", 
        new MatchEvaluator(match => match.Value.ToLower().Insert(1, " ")));

    return str;
}