CSHARP

c# make first letter uppercase

        System.Console.WriteLine(char.ToUpper(str[0]) + str.Substring(1));

first letter uppercase c#

// first letter of string
private string CapitalizeFirst (string input) {
  	char.ToUpper(myString[0]) + myString[1..]; // captalizes first letter
}

// first letter of each word
private string CapitalizeAll (string input) {
  	var words = input.Split(' '); // create array of words

  	// loop through all words and capitalize them
	for (int i = 0; i < words.length; i++) {
     	words[i] = CapitalizeFirst (words[i]);
    }
  
  	return string.Join(' ', words);
}

string myString = "hello world";

// results
CapitalizeFirst(myString); // "Hello world"
CapitalizeAll(myString); // "Hello World"

first sentence letter capital in c#

public static class StringExtension
{
    public static string CapitalizeFirst(this string s)
    {
        bool IsNewSentense = true;
        var result = new StringBuilder(s.Length);
        for (int i = 0; i < s.Length; i++)
        {
            if (IsNewSentense && char.IsLetter(s[i]))
            {
                result.Append (char.ToUpper (s[i]));
                IsNewSentense = false;
            }
            else
                result.Append (s[i]);

            if (s[i] == '!' || s[i] == '?' || s[i] == '.')
            {
                IsNewSentense = true;
            }
        }

        return result.ToString();
    }
}