Best way to convert Pascal Case to a sentence

Question

What is the best way to convert from Pascal Case (upper Camel Case) to a sentence.

For example starting with

\"AwaitingFeedback\"

a

Answer 1

Mostly already answered here

Small chage to the accepted answer, to convert the second and subsequent Capitalised letters to lower case, so change

if (char.IsUpper(text[i]))                
    newText.Append(' ');            
newText.Append(text[i]);

to

if (char.IsUpper(text[i]))                
{
    newText.Append(' ');            
    newText.Append(char.ToLower(text[i]));
}
else
   newText.Append(text[i]);

Answer 2

Here you go...

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace CamelCaseToString
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine(CamelCaseToString("ThisIsYourMasterCallingYou"));   
        }

        private static string CamelCaseToString(string str)
        {
            if (str == null || str.Length == 0)
                return null;

            StringBuilder retVal = new StringBuilder(32);

            retVal.Append(char.ToUpper(str[0]));
            for (int i = 1; i < str.Length; i++ )
            {
                if (char.IsLower(str[i]))
                {
                    retVal.Append(str[i]);
                }
                else
                {
                    retVal.Append(" ");
                    retVal.Append(char.ToLower(str[i]));
                }
            }

            return retVal.ToString();
        }
    }
}

Answer 3

public static string ToSentenceCase(this string str)
{
    return Regex.Replace(str, "[a-z][A-Z]", m => m.Value[0] + " " + char.ToLower(m.Value[1]));
}

In versions of visual studio after 2015, you can do

public static string ToSentenceCase(this string str)
{
    return Regex.Replace(str, "[a-z][A-Z]", m => $"{m.Value[0]} {char.ToLower(m.Value[1])}");
}

Based on: Converting Pascal case to sentences using regular expression

Answer 4

Most of the preceding answers split acronyms and numbers, adding a space in front of each character. I wanted acronyms and numbers to be kept together so I have a simple state machine that emits a space every time the input transitions from one state to the other.

    /// <summary>
    /// Add a space before any capitalized letter (but not for a run of capitals or numbers)
    /// </summary>
    internal static string FromCamelCaseToSentence(string input)
    {
        if (string.IsNullOrEmpty(input)) return String.Empty;

        var sb = new StringBuilder();
        bool upper = true;

        for (var i = 0; i < input.Length; i++)
        {
            bool isUpperOrDigit = char.IsUpper(input[i]) || char.IsDigit(input[i]);
            // any time we transition to upper or digits, it's a new word
            if (!upper && isUpperOrDigit)
            {
                sb.Append(' ');
            }
            sb.Append(input[i]);
            upper = isUpperOrDigit;
        }

        return sb.ToString();
    }

And here's some tests:

    [TestCase(null, ExpectedResult = "")]
    [TestCase("", ExpectedResult = "")]
    [TestCase("ABC", ExpectedResult = "ABC")]
    [TestCase("abc", ExpectedResult = "abc")]
    [TestCase("camelCase", ExpectedResult = "camel Case")]
    [TestCase("PascalCase", ExpectedResult = "Pascal Case")]
    [TestCase("Pascal123", ExpectedResult = "Pascal 123")]
    [TestCase("CustomerID", ExpectedResult = "Customer ID")]
    [TestCase("CustomABC123", ExpectedResult = "Custom ABC123")]
    public string CanSplitCamelCase(string input)
    {
        return FromCamelCaseToSentence(input);
    }