How to make a first letter capital in C#

Question

How can the first letter in a text be set to capital?

Example:

it is a text.  = It is a text.

Solution 1

public static string ToUpperFirstLetter(this string source)
{
    if (string.IsNullOrEmpty(source))
        return string.Empty;
    // convert to char array of the string
    char[] letters = source.ToCharArray();
    // upper case the first char
    letters[0] = char.ToUpper(letters[0]);
    // return the array made of the new char array
    return new string(letters);
}

Solution 2

It'll be something like this:

// precondition: before must not be an empty string
String after = before.Substring(0, 1).ToUpper() + before.Substring(1);

Solution 3

polygenelubricants' answer is fine for most cases, but you potentially need to think about cultural issues. Do you want this capitalized in a culture-invariant way, in the current culture, or a specific culture? It can make a big difference in Turkey, for example. So you may want to consider:

CultureInfo culture = ...;
text = char.ToUpper(text[0], culture) + text.Substring(1);

or if you prefer methods on String:

CultureInfo culture = ...;
text = text.Substring(0, 1).ToUpper(culture) + text.Substring(1);

where culture might be CultureInfo.InvariantCulture, or the current culture etc.

For more on this problem, see the Turkey Test.

Solution 4

If you are using C# then try this code:

Microsoft.VisualBasic.StrConv(sourceString, Microsoft.VisualBasic.vbProperCase)

Solution 5

I use this variant:

 private string FirstLetterCapital(string str)
        {
            return Char.ToUpper(str[0]) + str.Remove(0, 1);            
        }

View more solutions

Comments

[polygenelubricants]

Can the string be something like "99c waffles" and you want to get "99c Waffles"? That is, what is your definition of "first letter"?

[Jeroen]

possible duplicate of Make first letter of a string upper case

[Alastair Pitts]

You don't need to do the source.ToCharArray(). A string is already a char array and can be indexed with just source[0].

[Alastair Pitts]

This is ugly. If your using C#, why would you be importing/referencing the Visual Basic DLL?

[Jacob]

@Alastair, strings are immutable but char arrays aren't.

[Alastair Pitts]

@Jacob, Oooh yeah. Shows how dead my brain is on a Friday afternoon :/

[Cheng Chen]

Consider about different CultrueInfos, as well as TextInfos.

[Matt Mills]

@Jon Skeet - That was entirely my intent :) I was actually wondering what the performance would be compared to the substring method above.

[polygenelubricants]

@Danny: let's discuss your comment here stackoverflow.com/questions/3474578/…

[Vladislav Rastrusny]

.NET is also slow. C++ or assembler is much faster. Does that mean we need to drop .NET and move to faster languages?

[Jon Skeet]

@steven: You can use VB libraries from C#.

[Jon Skeet]

@Danny: Substring makes the code simple. I prefer to write simple code first, and then optimize with more complicated code only where necessary.

[Admin]

tell me the most case when we need to import Microsoft.VisualBasic dll when we work on C#.net

[Yves M.]

Can I suggest you to write if (string.IsNullOrEmpty(source)) return source; instead of string.Empty? :D

[Yves M.]

And also renaming the method from ToUpperFirstLetter to ToUpperFirstCharacter which is a more relevant name :)

[Wim Ombelets]

char[] nm = "this is a test".ToCharArray(); will work

[Murat Yıldız]

Taking consideration "CultureInfo" has made the solution perfect... Thanks a lot also for Turkey Test :)

[haroonxml]

Microsoft.VisualBasic.Strings.StrConv("hello", VbStrConv.ProperCase);

[General Grievance]

It's wrong anyway. This capitalizes every word, not just the first. Here's the VB function in action Try it online!