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Best way to repeat a character in C#

Asked 2009-01-04T21:56:59.597
1067

What is the best way to generate a string of \t's in C#?

I am learning C# and experimenting with different ways of saying the same thing.

Tabs(uint t) is a function that returns a string with t amount of \t's

For example, Tabs(3) returns "\t\t\t"

Which of these three ways of implementing Tabs(uint numTabs) is best?

Of course that depends on what "best" means.

  1. The LINQ version is only two lines, which is nice. But are the calls to Repeat and Aggregate unnecessarily time/resource consuming?

  2. The StringBuilder version is very clear, but is the StringBuilder class somehow slower?

  3. The string version is basic, which means it is easy to understand.

  4. Does it not matter at all? Are they all equal?

These are all questions to help me get a better feel for C#.

private string Tabs(uint numTabs)
{
    IEnumerable<string> tabs = Enumerable.Repeat("\t", (int) numTabs);
    return (numTabs > 0) ? tabs.Aggregate((sum, next) => sum + next) : "";
}

private string Tabs(uint numTabs)
{
    StringBuilder sb = new StringBuilder();
    for (uint i = 0; i < numTabs; i++)
        sb.Append("\t");

    return sb.ToString();
}

private string Tabs(uint numTabs)
{
    string output = "";
    for (uint i = 0; i < numTabs; i++)
    {
        output += '\t';
    }
    return output;
}
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3 Answers

1939

What about this:

string tabs = new string('\t', n);

Where n is the number of times you want to repeat the string.

Or better:

static string Tabs(int n)
{
    return new string('\t', n);
}
answered 2009-01-04T22:00:39.060
26

How about this:

//Repeats a character specified number of times
public static string Repeat(char character,int numberOfIterations)
{
    return "".PadLeft(numberOfIterations, character);
}

//Call the Repeat method
Console.WriteLine(Repeat('\t',40));
answered 2011-06-20T13:50:01.230
15

Using String.Concat and Enumerable.Repeat which will be less expensive than using String.Join

public static Repeat(this String pattern, int count)
{
    return String.Concat(Enumerable.Repeat(pattern, count));
}
answered 2013-04-23T07:09:24.450

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