Truncating a version number C#

Question

If I have a version number that has 5 digits such as "1.0.420.50.0", how could I truncate this number (and other version numbers like "1.0.512.500.0") to only 4 digits? "1.0.420.50.0" --> "1.0.420.50"

I would prefer to use an array but any other methods work too! Thanks for any advice in advance!

var newString = String.Join(".", oldString.Split('.').Take(4)); — Hans Passant, Aug 06 '15 at 18:51

Speerian · Accepted Answer · 2015-08-06T19:00:04.687

7

I haven't programmed in c# in a while so the syntax may be off. If the versioning can be more than six digits, you won't want a method that relies on removing the last digit. Instead just take the first four version numbers.

String version = "1.0.420.50.0";
String [] versionArray = version.Split(".");
var newVersion = string.Join(".", versionArray.Take(4));

edited Aug 06 '15 at 19:00

answered Aug 06 '15 at 18:56

Speerian

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You could do `var newVersion = string.Join(".", versionArray.Take(4));` instead. That would work even if the original has less than 4. – juharr Aug 06 '15 at 18:57
You don't need that last line now as `string.Join` doesn't add a trailing delimiter. – juharr Aug 06 '15 at 18:59
@juharr Thanks! I wasn't aware of string.Join. – Speerian Aug 06 '15 at 18:59

score 0 · Answer 2 · answered Aug 06 '15 at 18:51

If it's a string, you could do something like

ver = "1.2.3.4.5";
ver = ver.substring(0, ver.lastindexof(".");

this should give you all the way up to the last ".". This is not very robust if your version numbers get longer or shorter, but it would work for a 5 digit version number. This is also the basic idea you want if you have a string.

Nicholas Ellingson · Answer 3 · 2015-08-06T19:01:53.673

Get the index of the last period and then get the substring from index 0 to the index of the last period. EX:

string version = "1.0.420.50.0";
int lastPeriodIndex = version.LastIndexOf('.');
string reformattedVersion = version.Substring(0, lastPeriodIndex);

through using an array, if that's what you really want:

string version = "1.0.420.50";
var numbers = version.Split(new char[]{'.'}, StringSplitOptions.RemoveEmptyEntries);
string reformattedVersion = numbers[0] + '.' + numbers[1] + '.' + numbers[2] + '.' + numbers[3];

but that's a much less elegant/quick solution.

Truncating a version number C#

3 Answers3