C＃正则表达式拆分为非零数字，后跟任意数字零

Question

I have a number as a string "10009003" i would like to split it using regex to always get the first non-zero digit and include all trailing zeroes. Then get the next non-zero number followed by its trailing zeroes. If a non-zero number has no trailing zeroes just grab it.

The above number string should result in array/list of length/count 3 as follows [0] = 1000, [1] = 900, [2] =3

I have tried this code;

var someNumberString = "10009003";     
string s = @"[^1-9]+";
string[] strArray = Regex.Split(someNumberString, s);

which only output the following but the zeros are missing; [0] = 1 , [1] = 9 , [2] = 3

How do i get the regex to include the trailing zeros?

Thanks in advance for the help:)

Answer 1

You can use this lookbehind and lookahead based regex:

var someNumberString = "10009003";     
string s = @"(?<=[1-9]0*)(?=[1-9])";
string[] strArray = Regex.Split(someNumberString, s);

Console.Write(string.Join(" ", strArray));
//=> 1000 900 3

Online Demo

Explanation:

• (?<=[1-9]0*) ( Lookbehind ) - if current position preceded by a non-zero digit and 0 or more zeroes
• (?=[1-9]) ( Lookahead ) - if current position is followed by a non-zero digit

Answer 2

You could use regex.Matches function like below.

String input = @"10009003";
Regex rgx = new Regex(@"[1-9]+0*");
foreach (Match m in rgx.Matches(input))
Console.WriteLine(m.Groups[0].Value);

[1-9] matches the digit which ranges from 1 to 9. 0* matches zero or more 0 's.

IDEONE