How to Fix: Uppercase first letter of every word in the string - except for one letter words

Question

I have a code to capitalize the first letter of every words except for one letter words. The problem I have is if the last word of that string is one letter, it gives a index out of range exception. Which makes sense because the code array[i + 1] doesn't exist for the last letter.

static string UppercaseWords(string value)
        {
            char[] array = value.ToLower().ToCharArray();
            // Handle the first letter in the string.

            array[0] = char.ToUpper(array[0]);
            // Scan through the letters, checking for spaces.
            // ... Uppercase the lowercase letters following spaces.
            for (int i = 1; i < array.Length; i++)
            {
                if (array[i - 1] == ' ' && array[i + 1] != ' ') 
                {
                    array[i] = char.ToUpper(array[i]);
                }
            }
            return new string(array);
        }

I'm just looking for something to get around that exception, or another way to do this. Thank you.

Answer 1

您可以改善条件，这样就不会要求第（i + 1）个索引。

if (array[i - 1] == ' ' && i + 1 < array.Length && array[i + 1] != ' ') 

Answer 2

You could extract all the words (string parts separated by a white space) and convert to uppercase the first letter of the string part when the part length is > 1 :

string input = "this is a sample, string with: some => 1 letter words ! a";

StringBuilder sb = new StringBuilder(input.Length * 2);
foreach (string word in input.Split())
{
    if (word.Length > 1) {
        sb.Append(char.ToUpper(word[0]));
        sb.Append(word.Substring(1));
    }
    else {
        sb.Append(word);
    }
    sb.Append((char)32);
}
Console.WriteLine(sb);

Prints:

This Is a Sample, String With: Some => 1 Letter Words ! a

Answer 3

Suggestion:

I would do an extension class for your string handling :

public static class StringExtensions
{
    public static string AllWordsInStringToUpperCase(this string value)
    {
        return string.Join(' ', value.Split(' ').Select(s => s.FirstCharToUpperCase()));
    }

    public static string FirstCharToUpperCase(this string word)
    {
        if (word.Length == 1)
            return word;

        return word.First().ToString().ToUpper() + word.Substring(1);
    }
}

Than use it like this for en example in an Console application:

class Program
{
    static void Main(string[] args)
    {
        Console.WriteLine("fuu a bar".AllWordsInStringToUpperCase());
    }
}

Output: Fuu a Bar

By that you can write some test so you know you get the behavior you want.

Peace!