1028

I want to add a comma in the thousands place for a number.

Would String.Format() be the correct path to take? What format would I use?

GEOCHET
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Seibar
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23 Answers23

1503
$"{1234:n}";  // Output: 1,234.00
$"{9876:n0}"; // No digits after the decimal point. Output: 9,876
AHaleIII
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Seibar
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    How can I replicate the "N" specifier but with as many decimal digits as are present in the number? – Stephen Drew Nov 23 '12 at 10:33
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    @Justin: According to http://msdn.microsoft.com/en-us/library/0c899ak8.aspx, the ',' (and the '.') are replaced with the correct localized characters. – Roger Lipscombe Mar 04 '13 at 09:29
  • Short and easy to read, but the integer is boxed when passed as an argument. I prefer @alchemical 's answer to this. – Attila Klenik Aug 04 '15 at 19:30
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    If you want to force a decimal format on your page other than the system defined format, you can change the `CurrentCulture` like this example: `var nlBE = new System.Globalization.CultureInfo("nl-BE"); nlBE.NumberFormat.CurrencyDecimalDigits = 2; nlBE.NumberFormat.CurrencyDecimalSeparator = ","; nlBE.NumberFormat.CurrencyGroupSeparator = "."; System.Threading.Thread.CurrentThread.CurrentCulture = nlBE;` – DerpyNerd Oct 11 '16 at 06:05
  • for me it is not working using `"{0:n0}"` still gives me `2.40` – Nad Aug 11 '17 at 14:23
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    @VVVV - then you are probably passing in a *string* instead of a *number*. If you have a string, you need to first convert to float or double. Try `string.Format("{0:n0}", Double.Parse(yourValue));` – ToolmakerSteve Oct 26 '17 at 02:51
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    To replicate the behavior of the `n` specifier, but with as many decimal digits that are present in the number itself, I had to go with this format string instead `#,##0.##` (from another answer here) – evilkos Feb 14 '18 at 09:37
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    string interpolation is even shorter shorthand `$"{myVariable:n0}"` – R-D Apr 08 '20 at 19:34
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    I am in India, this gives wrong answer. Ex: 123456 → 1,23,456 So you need to specify invariant culture – Chandraprakash Oct 06 '21 at 15:05
471

I found this to be the simplest way:

myInteger.ToString("N0")
Jon Schneider
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alchemical
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165
int number = 1000000000;
string whatYouWant = number.ToString("#,##0");
//You get: 1,000,000,000
p.campbell
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    This solution is not good from an internationalisation point of view - other cultures use characters other than `,` as a thousands separator, for example a space or even `.`. – Justin Jan 31 '12 at 17:04
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    Works thanks + 1. Have extended so shows up to 2 d.p. number.ToString("#,##0.##") – Crab Bucket Mar 30 '12 at 10:38
  • @Justin This is true, but sometimes requirements are stupid, and requirements are requirements. :) Terrapin's method would be superior given enough flexibility, though, as you've pointed out. – Mac Sigler Jun 06 '13 at 22:29
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    @MacSigler It's actually not true, see Roger Lipscombe's comment on the answer above: String.Format will apply localization automatically. – Dan Bechard Oct 17 '13 at 19:34
  • @Dan What I was saying is that it's the most concise way given the requirement that a comma must always be printed out, whether on an American or British or Chinese computer. "1.000.000.000" would be incorrect, because the (admittedly silly, but not uncommon) requirements demand commas. I suppose you could go through and make a special localization, but that would be overkill. – Mac Sigler Oct 18 '13 at 17:22
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    @MacSigler That's the thing though, this code **does not** _always_ print out a comma. Only when the culture is one that expects commas (e.g. en-US or invariant). If the culture is one that expects another separator (e.g. `.`), .NET will automatically replace the comma with that separator. Again, I urge you to read the link posted by Roger if you still do not understand why this is. – Dan Bechard Oct 18 '13 at 18:33
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    @Dan So I went ahead and read the link already. It sounds like it already accounts for the culture, meaning that Justin's comment would be incorrect (unless it's required to specifically have output that is foreign to the user's culture)? In any case, +1 for pointing out something about .NET I didn't know before and being patient with my stubborn ignorance. :) – Mac Sigler Oct 21 '13 at 17:56
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    @MacSigler Justin's comment is still correct in that if you don't explicitly force the culture to en-US it will inherit culture settings from the local machine. My understanding is that compiling the code above, then running it on two machines with different cultures (with different number separators) would produce different results. If you want it to _always_ produce a comma, you need to explicitly set a culture that uses the comma (e.g. invariant). – Dan Bechard Oct 22 '13 at 14:12
126

If you want culture specific, you might want to try this:

use namespace:"using System.Globalization;"

(19950000.0).ToString("N",new CultureInfo("en-US")) = 19,950,000.00

(19950000.0).ToString("N",new CultureInfo("is-IS")) = 19.950.000,00

Indian culture: (19950000.0).ToString("N",new CultureInfo("hi-IN"))= 1,99,50,000.00

Note: Some cultures use , to mean decimal rather than . so be careful.

prabir
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99

Standard formats, with their related outputs,

Console.WriteLine("Standard Numeric Format Specifiers");
String s = String.Format("(C) Currency: . . . . . . . . {0:C}\n" +
                    "(D) Decimal:. . . . . . . . . {0:D}\n" +
                    "(E) Scientific: . . . . . . . {1:E}\n" +
                    "(F) Fixed point:. . . . . . . {1:F}\n" +
                    "(G) General:. . . . . . . . . {0:G}\n" +
                    "    (default):. . . . . . . . {0} (default = 'G')\n" +
                    "(N) Number: . . . . . . . . . {0:N}\n" +
                    "(P) Percent:. . . . . . . . . {1:P}\n" +
                    "(R) Round-trip: . . . . . . . {1:R}\n" +
                    "(X) Hexadecimal:. . . . . . . {0:X}\n",
                    - 1234, -1234.565F);
Console.WriteLine(s);

Example output (en-us culture):

(C) Currency: . . . . . . . . ($1,234.00)
(D) Decimal:. . . . . . . . . -1234
(E) Scientific: . . . . . . . -1.234565E+003
(F) Fixed point:. . . . . . . -1234.57
(G) General:. . . . . . . . . -1234
    (default):. . . . . . . . -1234 (default = 'G')
(N) Number: . . . . . . . . . -1,234.00
(P) Percent:. . . . . . . . . -123,456.50 %
(R) Round-trip: . . . . . . . -1234.565
(X) Hexadecimal:. . . . . . . FFFFFB2E
CoderTao
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    This answer packed a lot of useful information. Learning by example I see now what the 0 and 1 mean in the string format. – user420667 Nov 02 '16 at 16:58
  • Wow, really nice explanation – Mohamad Osama Apr 19 '22 at 15:38
  • The only question I have is, if the number provided is negative, why is currency positive? –  Sep 03 '22 at 18:29
  • @RWolfe Sometimes in business negative currency values are displayed as being inside parentheses instead of with a negative sign. Eg. the value `-1234.56` would be displayed as `($1,234.56)` and the value `6543.21` would be displayed as `$6,543.21`. – Joseph Terribile Sep 03 '22 at 22:01
63

This is the best format. Works in all of those cases:

String.Format( "{0:#,##0.##}", 0 ); // 0
String.Format( "{0:#,##0.##}", 0.5 ); // 0.5 - some of the formats above fail here. 
String.Format( "{0:#,##0.##}", 12314 ); // 12,314
String.Format( "{0:#,##0.##}", 12314.23123 ); // 12,314.23
String.Format( "{0:#,##0.##}", 12314.2 ); // 12,314.2
String.Format( "{0:#,##0.##}", 1231412314.2 ); // 1,231,412,314.2
Dennis
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46

The most voted answer was great and has been helpful for about 7 years. With the introduction of C# 6.0 and specifically the String Interpolation there's a neater and, IMO safer, way to do what has been asked to add commas in thousands place for a number:

var i = 5222000;
var s = $"{i:n} is the number"; // results to > 5,222,000.00 is the number
s = $"{i:n0} has no decimal"; // results to > 5,222,000 has no decimal

Where the variable i is put in place of the placeholder (i.e. {0}). So there's no need to remember which object goes to which position. The formatting (i.e. :n) hasn't changed. For a complete feature of what's new, you may go to this page.

von v.
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40

just simple as this:

float num = 23658; // for example 
num = num.ToString("N0"); // Returns 23,658

more info is in Here

amdev
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36
String.Format("{0:#,###,###.##}", MyNumber)

That will give you commas at the relevant points.

Dan
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Stephen Wrighton
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    The ":n" method is better since it should respect the user's locale. – Torlack Sep 19 '08 at 21:30
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    This is true, but it's not guaranteed to give you commas at the thousand point because it respect the user's locale. – Stephen Wrighton Sep 19 '08 at 21:35
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    right back at you: that is true, but it's not guaranteed to respect the user's locale because it uses commas as thousands separator. (As an example, in Portugal the comma is instead the decimal separator.) – ANeves May 19 '10 at 17:46
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    If you want to enforce values after the . you need to replace the # with a 0. http://msdn.microsoft.com/en-us/library/0c899ak8(v=vs.110).aspx: Zero replaces the zero with the corresponding digit if one is present; otherwise, zero appears in the result string whereas the "#" symbol is replaced with the corresponding digit if one is present; otherwise, no digit appears in the result string. – Clarice Bouwer Feb 06 '14 at 09:29
  • this method worked ok for my requirement, the msdn page about the Int32.ToString method that would be a primary place it would be used http://msdn.microsoft.com/en-us/library/8wch342y.aspx isn't very helpful for this particular application either – stackuser83 Mar 25 '14 at 00:24
  • the only recommendation is string with capital S it is a convention... result is same... but String.format("{0:#,###,###.##}", MyNumber) – Valentin Petkov May 06 '14 at 13:16
  • When MyNumber is 0, returns an empty string instead of "0" – HelloWorld Sep 22 '15 at 07:21
24

The following example displays several values that are formatted by using custom format strings that include zero placeholders.

String.Format("{0:N1}", 29255.0);

Or

29255.0.ToString("N1")

result "29,255.0"

String.Format("{0:N2}", 29255.0);

Or

29255.0.ToString("N2")

result "29,255.00"

Yitzhak Weinberg
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22

C# 7.0+ makes this as easy and nice-looking as it should be, with string interpolation:

var jackpot = 1_000_000; // underscore separators in numeric literals also available since C# 7.0
var niceNumberString = $"Jackpot is {jackpot:n}"; 
var niceCurrencyString = $"Jackpot is {jackpot:C}";

Console.WriteLine(niceNumberString); // output: "Jackpot is 1,000,000.00"
Console.WriteLine(niceCurrencyString); // output: "Jackpot is ¤1,000,000.00"

Note '¤' in the output for the niceCurrencyString example will be the currency symbol as associated with System.Threading.Thread.CurrentThread.CurrentCulture, e.g. if "en-US" it will be a '$' sign.

Mark Z.
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    wow this is really neat and clean, didn't know c# has that, thanks! – coster128 Jun 13 '20 at 01:16
  • Actually it is/was 7.0, see: https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/proposals/csharp-7.0/digit-separators – Luuk Jan 02 '22 at 17:58
21

If you wish to force a "," separator regardless of culture (for example in a trace or log message), the following code will work and has the added benefit of telling the next guy who stumbles across it exactly what you are doing.

int integerValue = 19400320; 
string formatted = string.Format(CultureInfo.InvariantCulture, "{0:N0}", integerValue);

sets formatted to "19,400,320"

Ravi Desai
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14

Simpler, using string interpolation instead of String.Format

 $"{12456:n0}"; // 12,456
 $"{12456:n2}"; // 12,456.00

or using yourVariable

 double yourVariable = 12456.0;
 $"{yourVariable:n0}"; 
 $"{yourVariable:n2}"; 
brakeroo
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11

For example String.Format("{0:0,0}", 1); returns 01, for me is not valid

This works for me

19950000.ToString("#,#", CultureInfo.InvariantCulture));

output 19,950,000

cmujica
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  • but if we take 19950000 value into variable and do like this var test = "19950000"; test.ToString("#,#", CultureInfo.InvariantCulture)); its not wokring – Neo Sep 28 '20 at 06:45
11
int num = 98765432;
Console.WriteLine(string.Format("{0:#,#}", num));
p.campbell
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    Or Console.WriteLine("{0:#,#}",num); if you just want to print it. But string.Format(...) is more useful I guess. – Indy9000 Aug 25 '11 at 14:42
9

Note that the value that you're formatting should be numeric. It doesn't look like it will take a string representation of a number and format is with commas.

6
String.Format("0,###.###"); also works with decimal places
Abolfazl Rastgou
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You can use a function such as this to format numbers and optionally pass in the desired decimal places. If decimal places are not specified it will use two decimal places.

    public static string formatNumber(decimal valueIn=0, int decimalPlaces=2)
    {
        return string.Format("{0:n" + decimalPlaces.ToString() + "}", valueIn);
    }

I use decimal but you can change the type to any other or use an anonymous object. You could also add error checking for negative decimal place values.

dunwan
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3

You want same Format value and culture specific.

 Double value= 1234567;
 value.ToString("#,#.##", CultureInfo.CreateSpecificCulture("hi-IN"));

Output: 12,34,567

1

I tried many of the suggestions above but the below work better for me:

string.Format("{0:##,###.00}", myValue)

but this fails when you have values like 0.2014 where it gives .21 For this I use

string.Format("{0:#,##0.00}", myValue)
Yusuff Sodiq
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0

Try this:

var number = 123456789;
var str = number.ToString("N0");

Result is: "123,456,789"

Sepideh I
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-3

The method I used to not worry anymore about cultures and potential formatting issues is that I formatted it as currency and took out the currency symbol afterwards.

if (decimal.TryParse(tblCell, out result))

{
  formattedValue = result.ToString("C").Substring(1);
}
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    This code is not culture independent - it will use whatever default culture is set on the machine running the code. This could create undesired output where that culture places their currency symbols at the end of the number rather than the start (e.g. `fr-FR`), or uses more than one character to denote the currency (e.g. `da-DK`), or does not separate thousands using commas (e.g. most of mainland Europe). – raveturned Jun 13 '12 at 21:08
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If you want to show it in DataGridview , you should change its type , because default is String and since you change it to decimal it considers as Number with floating point

Dim dt As DataTable = New DataTable
dt.Columns.Add("col1", GetType(Decimal))
dt.Rows.Add(1)
dt.Rows.Add(10)
dt.Rows.Add(2)

DataGridView1.DataSource = dt
Ali
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