Title Case in VB.net or C#

Introduction

Format book titles or TV series titles as the MLA style. 

Background

Today, I was writing a function dealing with title case.

I firstly tried to look for code in C# which deals with it, but all I found was actually first-letter-capital solutions. Like this one in StackOverFlow.com.

http://stackoverflow.com/questions/1206019/converting-string-to-title-case-in-c-sharp

 

However, what I wanted was first-letter-capital but escape words such as the, a, in, of, and words like USA, UK, TV should be all capital. Or to say I wanted the MLA(Modern Language association) style. The official definition is here:

https://www.ivcc.edu/stylebooks/stylebook4.aspx?id=14718

Capitalizing Titles

Capitalize the first letter of the major words of titles. Minor words, such as articles, prepositions, and coordinating conjunctions, are not capitalized unless they are the first word of a title or subtitle.

“Why Boys Don’t Play with Dolls” (a short essay) 

In the Heat of the Night (a film)

I finally found the functionality that I wanted but not the code.

http://www.titlecase.com/

Using the code

Unfortunately, I had to write the code by myself, and I meant to follow the MLA style. For the acronyms, because my project was related to TV shows so words such as US, UK, BBC are frequently used. You can modify the list and add your own acronyms.

    <Extension()>
    Public Function ToTitleCase(ByRef s As String) As String

        Dim upperCase = s.ToUpper()
        Dim words = upperCase.Split(" ")

        'prepositions, articles and conjunctions
        Dim minorWords = New String() {"ON", "IN", "AT", "OFF", "WITH", "TO", "AS", "BY",
                                       "THE", "A", "OTHER", "ANOTHER",
                                       "AND", "BUT", "ALSO", "ELSE", "FOR", "IF"}
        'countries, TV stations and others
        Dim acronyms = New String() {"UK", "USA", "US",
                                       "BBC",
                                       "TV"}

        'The first word.
        'The first letter of the first word is always capital.
        If acronyms.Contains(words(0)) Then
            words(0) = words(0).ToUpper()
        Else
            words(0) = words(0).ToPascalCase()
        End If

        'The rest words.
        For i As Integer = 1 To words.Length - 1
            If minorWords.Contains(words(i)) Then
                words(i) = words(i).ToLower()
            ElseIf acronyms.Contains(words(i)) Then
                words(i) = words(i).ToUpper()
            Else
                words(i) = words(i).ToPascalCase()
            End If
        Next

        Return String.Join(" ", words)

    End Function

    <Extension()>
    Public Function ToPascalCase(ByRef s As String) As String
        Return s.Substring(0, 1).ToUpper() + s.Substring(1).ToLower()
    End Function

Test Cases

    <TestMethod()>
    Public Sub ToTitleCaseTest()
        Debug.Print("USA".ToTitleCase())
        Debug.Print("usa".ToTitleCase())
        Debug.Print("uSa".ToTitleCase())
        Debug.Print("Sleepy Hollow".ToTitleCase())
        Debug.Print("Z Nation".ToTitleCase())
        Debug.Print("Hot In Cleveland".ToTitleCase())
        Debug.Print("HOT IN CLEVELAND".ToTitleCase())
        Debug.Print("once upon a time".ToTitleCase())
        Debug.Print("ONCE UPON A TIME".ToTitleCase())
    End Sub

Test Result

USA

USA

USA

Sleepy Hollow

Z Nation

Hot in Cleveland

Hot in Cleveland

Once Upon a Time

Once Upon a Time

C# Code

    public static class StringExtensions
    {
        public static string ToTitleCase(this string s)
        {

            var upperCase = s.ToUpper();
            var words = upperCase.Split(' ');

            var minorWords = new String[] {"ON", "IN", "AT", "OFF", "WITH", "TO", "AS", "BY",//prepositions
                                       "THE", "A", "OTHER", "ANOTHER",//articles
                                       "AND", "BUT", "ALSO", "ELSE", "FOR", "IF"};//conjunctions

            var acronyms = new String[] {"UK", "USA", "US",//countries
                                       "BBC",//TV stations
                                       "TV"};//others

            //The first word.
            //The first letter of the first word is always capital.
            if (acronyms.Contains(words[0]))
            {
                words[0] = words[0].ToUpper();
            }
            else
            {
                words[0] = words[0].ToPascalCase();
            }

            //The rest words.
            for (int i = 0; i < words.Length; i++)
            {
                if (minorWords.Contains(words[i]))
                {
                    words[i] = words[i].ToLower();
                }
                else if (acronyms.Contains(words[i]))
                {
                    words[i] = words[i].ToUpper();
                }
                else
                {
                    words[i] = words[i].ToPascalCase();
                }
            }

            return string.Join(" ", words);

        }

        public static string ToPascalCase(this string s)
        {
            return s.Substring(0, 1).ToUpper() + s.Substring(1).ToLower();
        }
    }