C# - Insert a variable number of spaces into a string? (Formatting an output file)

Question

Alrighty, I'm taking data from a list that I populate a DataGridView with and am exporting it to a text file. I've already done the function to export it to a CSV, and would like to do a plain text version as well.

Because the Titles and other elements are variable in length, when the file is saved and then opened in Notepad it looks like a mess because nothing lines up.

I'd like to have the output look like this:

Sample Title One   Element One   Whatever Else
Sample Title 2     Element 2     Whatever Else
S. T. 3            E3            Whatever Else

I figure that I can loop through each of the elements in order to get the length of the longest one so I can calculate how many spaces to add to each of the remaining element.

My main question is: Is there an elegant way to add a variable number of chars into a string? It'd be nice to have something like: myString.insert(index, charToInsert, howManyToInsert);

Of course, I can obviously just write a function to do this via a loop, but I wanted to see if there was a better way of doing it.

Thanks in advance!

-Sootah

Answer 1

For this you probably want myString.PadRight(totalLength, charToInsert).

See String.PadRight Method (Int32) for more info.

Answer 2

Use String.Format() or TextWriter.Format() (depending on how you actually write to the file) and specify the width of a field.

String.Format("{0,20}{1,15}{2,15}", "Sample Title One", "Element One", "Whatever Else");

You can specify the width of a field within interpolated strings as well:

$"{"Sample Title One",20}{"Element One",15}{"Whatever Else",15}"

And just so you know, you can create a string of repeated characters using the appropriate string contructor.

new String(' ', 20); // string of 20 spaces

Answer 3

Use String.Format:

string title1 = "Sample Title One";
string element1 = "Element One";
string format = "{0,-20} {1,-10}";

string result = string.Format(format, title1, element1);
//or you can print to Console directly with
//Console.WriteLine(format, title1, element1);

In the format {0,-20} means the first argument has a fixed length 20, and the negative sign guarantees the string is printed from left to right.

Answer 4

Just for kicks, here's the functions I wrote to do it before I had the .PadRight bit:

    public string insertSpacesAtEnd(string input, int longest)
    {
        string output = input;
        string spaces = "";
        int inputLength = input.Length;
        int numToInsert = longest - inputLength;

        for (int i = 0; i < numToInsert; i++)
        {
            spaces += " ";
        }

        output += spaces;

        return output;
    }

    public int findLongest(List<Results> theList)
    {
        int longest = 0;

        for (int i = 0; i < theList.Count; i++)
        {
            if (longest < theList[i].title.Length)
                longest = theList[i].title.Length;
        }
        return longest;
    }

    ////Usage////
    for (int i = 0; i < storageList.Count; i++)
    {
        output += insertSpacesAtEnd(storageList[i].title, longest + 5) +   storageList[i].rank.Trim() + "     " + storageList[i].term.Trim() + "         " + storageList[i].name + "\r\n";
    }

Answer 5

I agree with Justin, and the WhiteSpace CHAR can be referenced using ASCII codes here Character number 32 represents a white space, Therefore:

string.Empty.PadRight(totalLength, (char)32);

An alternative approach: Create all spaces manually within a custom method and call it:

private static string GetSpaces(int totalLength)
    {
        string result = string.Empty;
        for (int i = 0; i < totalLength; i++)
        {
            result += " ";
        }
        return result;
    }

And call it in your code to create white spaces: GetSpaces(14);