如果存在超过 37 个字符，如何将字符串拆分为多行

Question

how to split a string into multiple lines if more than 37 characters are present?

Example sentence

The Quick Brown Fox Jumped Over The Lazy Dog

It should make it

The Quick Brown Fox Jumped Over The
Lazy Dog

Although the 37th character is 'L'

I want to group by words.

Here is my code

private string sentence(string statement)
{
    string completedWord = "";
    string temp = "";
    string[] wordArray = statement.Split(' ');
    for (int i = 0; i < wordArray.Length; i++)
    {
        temp = completedWord + wordArray[i] + ' ';
        if (temp.Length < 37)
        {
            completedWord = completedWord + wordArray[i] + ' ';
        }
        else
        {
            completedWord = completedWord + "\n" + wordArray[i] + ' ';
        }
        temp = "";
    }
    return completedWord;
}

Once the sentence is 37 characters, it keeps doing else . I want each line to be 37 before adding \\n . This only happens if the sentence is much longer than 37 characters

Answer 1

This should do the trick. I'll use the StringBuilder for convenience, by the way.

static string sentence(string statement)
{
  if (statement.Length > 37)
  {
    var words = statement.Split(' ');        
    StringBuilder completedWord = new StringBuilder();
    int charCount = 0;

    if (words.Length > 1)
    {
      for (int i = 1; i < words.Length - 1; i++)
      {
        charCount += words[i].Length;
        if (charCount >= 37)
        {
          completedWord.AppendLine();
          charCount = 0;
        }

        completedWord.Append(words[i]);
        completedWord.Append(" ");
      }
    }

    // add the last word
    if (completedWord.Length + words[words.Length - 1].Length >= 37)
    {
      completedWord.AppendLine();
    }
    completedWord.Append(words[words.Length - 1]);
    return completedWord.ToString();
  }
  return statement;
}

Answer 2

You can just do the string substring method as like below,

 string WrapText(string statement, int Length)
        {            
            StringBuilder completedWord = new StringBuilder();

            completedWord.Append(statement.Substring(0, Length));//cut the specifed legth from long string
            completedWord.AppendLine();
            completedWord.Append(statement.Substring(Length));//read remainig letters
            return completedWord.ToString();
        }

Answer 3

I use this:

    /// <summary>
    /// Wrap lines in strings longer than maxLen by interplating new line
    /// characters.
    /// </summary>
    /// <param name="lines">the lines to process</param>
    /// <param name="maxLen">the maximum length of each line</param>
    public static string[] wrap_lines(string[] lines, int maxLen)
    {
        List<string> output = new List<string>();

        foreach (var line in lines)
        {
            var words = line.Split(' ');
            string newWord = words[0] + " ";
            int len = newWord.Length;

            for (int i = 1; i < words.Length; i++)
            {
                if (len + words[i].Length + 1 > maxLen)
                {
                    len = 0;
                    newWord += "\n";
                    i--;
                }
                else
                {
                    len += words[i].Length + 1;
                    string ch = i == words.Length - 1 ? "" : " ";
                    newWord += words[i] + ch;
                }
            }
            output.Add(newWord);
        }
        return output.ToArray();
    }

It assumes that no word is longer than maxLen .

Answer 4

Corrected your for loop:

for (int i = 0; i < wordArray.Length; i++)
            {
                //temp = completedWord + wordArray[i] + ' ';      //remove it
                temp = temp + wordArray[i] + ' ';    //added
                if (temp.Length < 37)
                {
                    completedWord = completedWord + wordArray[i] + ' ';
                }
                else
                {
                    completedWord = completedWord + "\n";    //corrected
                    temp = "";     //added
                }
                //temp = "";       //remove it
            }

Answer 5

You could include a field that records the number of lines currently recorded:

string completedWord = "";
    string temp = "";
    string[] wordArray = statement.Split(' ');
    int lines = 1;
    for (int i = 0; i < wordArray.Length; i++)
    {

        temp = completedWord + wordArray[i] + ' ';
        if (temp.Length < 37* lines)
        {
            completedWord = completedWord + wordArray[i] + ' ';
        }
        else
        {
            completedWord = completedWord + "\n" + wordArray[i] + ' ';
            lines += 1;
        }
        temp = "";
    }

Answer 6

Once you've added the first \\n, the string will always exceed 37 chars, so the first if(len<37) test will only return true once.

Instead, you need another var ie

string tempLine = "";

Then as you iterate over your word collection, build a line composed of words totaling <= 37 chars via tempLine, once you hit the max, add it to completedWord, then reset tempLine = "" before the next loop.

temp = tempLine + wordArray[i] + ' ';
if (temp.Length < 37)
{
    tempLine = tempLine + wordArray[i] + ' ';
}
else
{
    completedWord = completedWord + tempLine + "\n";
    tempLine = "";
}
temp = "";

Answer 7

Here's my go at it. Its a short little recursive function accepting the string you wish to break into multiple lines, and the maximum length (the cut off point) of each line, as parameters.

It takes a substring of the input text from the beginning to the desired linelength and adds it to an "output" variable. It then feeds the remainder of the input string back in to the function where it keeps recursively calling itself until the length of the remainder is less than the desired linelength, at which point it returns the output variable.

Hope that was clear.

    public static string breakString(string s, int lineLength){
    string output = "";
    if(s.Length > lineLength){
        output = output + s.Substring(0, lineLength) + '\n';
        string remainder = s.Substring(lineLength, s.Length-lineLength);
        output = output + breakString(remainder, lineLength, maxLines);
    } else {
        output = output + s;    
    }

    return output;

}

Answer 8

The currently accepted answer is overcomplex and not sure if accurate (see comments). A more simple and accurate solution is:

public static class StringExtensions
{
    public static string BreakLongLine(this string line, int maxLen, string newLineCharacter)
    {
        // if there is nothing to be split, return early
        if (line.Length <= maxLen)
        {
            return line;
        }

        StringBuilder lineSplit = new StringBuilder();

        var words = line.Split(' ');
        var charCount = 0;
        for (var i = 0; i < words.Length; i++)
        {
            if (charCount + words[i].Length >= maxLen)
            {
                // '>=' and not '>' because I need to add an extra character (space) before the word
                // and last word character should not be cut
                lineSplit.Append(newLineCharacter);
                charCount = 0;
            }

            if (charCount > 0)
            {
                lineSplit.Append(' ');
                charCount++;
            }

            lineSplit.Append(words[i]);
            charCount += words[i].Length;
        }

        return lineSplit.ToString();
    }
}

Please note that this solution:

1. do not leave spaces at the end of a line;
2. code is cleaner. For example, has fewer conditions and it returns early to improve code readiness

I also cover this method with unit tests so you can see that works:

public class StringExtensionsTests
{
    [Fact]
    public void SplitIntoTwoLines()
    {
        // arrange
        const string longString = "Four words two lines";

        // act
        var resultString = longString.BreakLongLine(10, "\n");

        // assert
        Assert.Equal("Four words\ntwo lines", resultString);
    }

    [Fact]
    public void SplitIntoThreeLines()
    {
        // arrange
        const string longString = "Four words two lines";

        // act
        var resultString = longString.BreakLongLine(9, "\n");

        // assert
        Assert.Equal("Four\nwords two\nlines", resultString);
    }

    // https://stackoverflow.com/questions/15793409/how-to-split-a-string-into-multiple-lines-if-more-than-37-characters-are-present
    [Fact]
    public void StackOverflowExample()
    {
        // arrange
        const string longString = "The Quick Brown Fox Jumped Over The Lazy Dog";

        // act
        var resultString = longString.BreakLongLine(37, "\n");

        // assert
        Assert.Equal("The Quick Brown Fox Jumped Over The\nLazy Dog", resultString);
    }
}