C# fix sentence

Question

I need to take a sentence in that is all on one line with no spaces and each new word has a captial letter EX. "StopAndSmellTheRoses" and then convert it to "Stop and smell the roses" This is my function that I have but I keep getting an argument out of range error on the insert method. Thanks for any help in advance.

private void FixSentence()
{
    // String to hold our sentence in trim at same time
    string sentence = txtSentence.Text.Trim();

    // loop through the string
    for (int i = 0; i < sentence.Length; i++)
    {
        if (char.IsUpper(sentence, i) & sentence[i] != 0)
        {
            // Change to lowercase
            char.ToLower(sentence[i]);

            // Insert space behind the character
            // This is where I get my error
            sentence = sentence.Insert(i-1, " ");
        }
    }

    // Show our Fixed Sentence
    lblFixed.Text = "";
    lblFixed.Text = "Fixed: " + sentence;
}

score 3 · Accepted Answer · answered Mar 25 '12 at 15:10

The best way to build up a String in this manner is to use a StringBuilder instance.

var sentence = txtSentence.Text.Trim();
var builder = new StringBuilder();
foreach (var cur in sentence) {
  if (Char.IsUpper(cur) && builder.Length != 0) {
    builder.Append(' ');
  }
  builder.Append(cur);
}

// Show our Fixed Sentence
lblFixed.Text = "";
lblFixed.Text = "Fixed: " + builder.ToString();

Using the Insert method creates a new string instance every time resulting in a lot of needlessly allocated values. The StringBuilder though won't actually allocate a String until you call the ToString method.

This worked i looked more into builder and it is defiantly the way to go. Thanks a lot — amedeiros, Mar 25 '12 at 15:33

score 1 · Answer 2 · answered Mar 25 '12 at 15:10

1

You can't modify the sentence variable in the loop that is going through it.

Instead, you need to have a second string variable that you append all of the found words.

answered Mar 25 '12 at 15:10

NotMe

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score 1 · Answer 3 · edited May 23 '17 at 12:15

1

Here is the answer

var finalstr = Regex.Replace(
        "StopAndSmellTheRoses",
        "(?<=[a-z])(?<x>[A-Z])|(?<=.)(?<x>[A-Z])(?=[a-z])|(?<=[^0-9])(?<x>[0-9])(?=.)",
        me => " " + me.Value.ToLower() 
    );

will output

Stop and smell the roses

edited May 23 '17 at 12:15

Community

1
1

answered Mar 25 '12 at 15:13

L.B

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score 0 · Answer 4 · answered Mar 25 '12 at 18:01

Another version:

public static class StringExtensions
{
  public static string FixSentence(this string instance)
  {
    char[] capitals = Enumerable.Range(65, 26).Select(x => (char)x).ToArray();
    string[] words = instance.Split(capitals);
    string result = string.Join(' ', words);
    return char.ToUpper(result[0]) + result.Substring(1).ToLower();
  }
}

C# fix sentence

4 Answers4

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