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I have a numeric string like this 2223,00. I would like to transform it to 2223. This is: without the information after the ",". Assume that there will be only two decimals after the ",".

I did:

str = str.Remove(str.Length - 3, 3);

Is there a more elegant solution? Maybe using another function? -I don´t like putting explicit numbers-

gotqn
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10 Answers10

175

You can actually just use the Remove overload that takes one parameter:

str = str.Remove(str.Length - 3);

However, if you're trying to avoid hard coding the length, you can use:

str = str.Remove(str.IndexOf(','));
Reed Copsey
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  • I received a lot of good answers. But this one is the one I will use, in terms of elegance. Nevertheless, I don´t know, in **low level**, which one is more efficient. So, make your choice! –  Nov 11 '11 at 19:24
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    The second solution is way easier to read, understand, and maintain, and in terms of **low level** performance, the difference is incredibly insignificant. If you KNOW that the `,` is always at position -3, then the first solution is still OK, but *premature optimization* is a terrible thing to waste your time on. – Scott Rippey Nov 11 '11 at 19:28
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    @Kani The first is the most efficient - but I completely agree with Scott. I would always choose the second, unless I knew, after profiling, that there was a perf. bottleneck here. Both of these (and most of the other answers) are going to be very fast -good enough for nearly all purposes. – Reed Copsey Nov 11 '11 at 20:24
  • Suppose you want the string to be unmodified if there's no comma? – Kyle Delaney Mar 30 '18 at 15:20
16

Perhaps this:

str = str.Split(",").First();
k.m
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  • I think this is the "most elegant" of the answers - at least so far. – Tom Bushell Nov 11 '11 at 19:10
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    what do you thing about the @ ReedCopsey one? I think is a very good one. –  Nov 11 '11 at 19:15
  • @Kani: in terms of elegance I find most of the answers posted *good enough*. I wouldn't be bothered with performance either, *unless* it really proves to be bottleneck. Only thing to consider is how do you want to deal with strings coming in different format... – k.m Nov 11 '11 at 19:38
  • Consider passing a second argument of `2` to `Split` because you don't care about any further commas. – Richard Nov 12 '11 at 17:27
5

This will return to you a string excluding everything after the comma

str = str.Substring(0, str.IndexOf(','));

Of course, this assumes your string actually has a comma with decimals. The above code will fail if it doesn't. You'd want to do more checks:

commaPos = str.IndexOf(',');
if(commaPos != -1)
    str = str.Substring(0, commaPos)

I'm assuming you're working with a string to begin with. Ideally, if you're working with a number to begin with, like a float or double, you could just cast it to an int, then do myInt.ToString() like:

myInt = (int)double.Parse(myString)

This parses the double using the current culture (here in the US, we use . for decimal points). However, this again assumes that your input string is can be parsed.

Christopher Currens
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4
String.Format("{0:0}", 123.4567);      // "123"

If your initial value is a decimal into a string, you will need to convert

String.Format("{0:0}", double.Parse("3.5", CultureInfo.InvariantCulture))  //3.5

In this example, I choose Invariant culture but you could use the one you want.

I prefer using the Formatting function because you never know if the decimal may contain 2 or 3 leading number in the future.

Edit: You can also use Truncate to remove all after the , or .

Console.WriteLine(Decimal.Truncate(Convert.ToDecimal("3,5")));
Patrick Desjardins
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  • Well, I´m getting the same number in this case, whit the **coma** on it. –  Nov 11 '11 at 19:05
  • What is the exact string you use and what culture is your computer? – Patrick Desjardins Nov 11 '11 at 19:07
  • Like in the example: **dddd,dd** , where **d** is a digit. The decimals are after the **,** in this case. I´m standardizing some results, deleting **.** and **,**, or using **.** instead of **,** –  Nov 11 '11 at 19:14
  • I don't know if I would use string.Format to do this personally. While it works, it winds up boxing the double before its passed to string.Format, thus creating an extra object. – Christopher Currens Nov 11 '11 at 19:14
  • I have to say that I do not know what is better in term of performance between playing with String (substring) or boxing. I do not think it really matter if it's not used intensively. Depend of the situation :) – Patrick Desjardins Nov 11 '11 at 19:18
  • @Daok, I totally agree, boxing only really matters if this were used in a large loop for example, since a new object would be allocated each iteration. – Christopher Currens Nov 11 '11 at 22:06
1

Use:

public static class StringExtensions
{
    /// <summary>
    /// Cut End. "12".SubstringFromEnd(1) -> "1"
    /// </summary>
    public static string SubstringFromEnd(this string value, int startindex)
    {
        if (string.IsNullOrEmpty(value)) return value;
        return value.Substring(0, value.Length - startindex);
    }
}

I prefer an extension method here for two reasons:

  1. I can chain it with Substring. Example: f1.Substring(directorypathLength).SubstringFromEnd(1)
  2. Speed.
Peter Mortensen
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Sebastian Ax
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1

You could use LastIndexOf and Substring combined to get all characters to the left of the last index of the comma within the sting.

string var = var.Substring(0, var.LastIndexOf(','));

Nothingman
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1

Since C# 8.0 it has been possible to do this with a range operator.

string textValue = "2223,00";
textValue = textValue[0..^3];
Console.WriteLine(textValue);

This would output the string 2223.

The 0 says that it should start from the zeroth position in the string

The .. says that it should take the range between the operands on either side

The ^ says that it should take the operand relative to the end of the sequence

The 3 says that it should end from the third position in the string

0

Try the following. It worked for me:

str = str.Split(',').Last();
Peter Mortensen
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0

You can use TrimEnd. It's efficient as well and looks clean.

"Name,".TrimEnd(',');
Peter Mortensen
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Abdul Munim
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    That will only remove any ',' characters that are at the end of the string. Since the string "123,45" ends with digits, `"123,45".TrimEnd(',')` will return "123,45". – phoog Nov 11 '11 at 18:57
  • `Remove last characters from a string if this character is... ` Just fits me well. Appreciated. `"oppa/ ".Trim().TrimEnd('/');` – it3xl May 04 '17 at 17:22
-3

Use lastIndexOf. Like:

string var = var.lastIndexOf(',');
Peter Mortensen
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shrey
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  • var is a variable name. It should never be used as a name for a string. -1; additionally this only gives the index, so it only solves part of the problem. You need the Remove(). – Patrick Knott Aug 09 '19 at 22:13