Format number with leading zeros and thousand separator

Question

I'd like to format an integer in a way that it has leading zeros and thousand separators at the same time.

I know that someInt.ToString("D6"); will give me leading zeros, but apparently it doesn't allow NumberGroupSeparator. On the other hand someInt.ToString("N"); will give me separators but no leading zeros...

Is it possible to combine both to print 123456 as 00 123 456? I know I can get string created with N and then manually add zeros to string in a loop or something, but maybe there's better way?

EDIT: Number of padding zeros (total digits length of number) should be adjustable.

Answer 1

If you want 00 123 456, just do:

123456.ToString("00 000 000")

If you need a fixed amount of zero's, all I can think of is this:

int NUM_LENGTH = 6;

//This is not very elegant
var NUM_STR = String.Join("", Enumerable.Range(0, NUM_LENGTH).Select((x, i) => (NUM_LENGTH - i) % 3 == 0 ? " 0" : "0"));

//But at least it works:
var example1 = 123456.ToString(NUM_STR); //Outputs  123 456
var example2 = 1234.ToString(NUM_STR); //Outputs 001 234

Answer 2

I think the following should work.

int value = 102145;
int num_length = 10; // it may change as you expected
string format = "000,000,000,000,000";
string tmp = value.ToString(format);
Console.Out.WriteLine(tmp.Substring(tmp.Length - num_length - tmp.Length/4 + 1 ));

Please let me know whether it works or not.

Corrected & working version:

int value = 102145;
int num_length = 12;
string format = "000,000,000,000,000,000";
string tmp = value.ToString(format);
int totalLength = format.Replace("000,", "000").Length;
int rem = (totalLength - num_length ) / 3;
Console.Out.WriteLine(tmp.Substring(totalLength - num_length + rem));

Answer 3

You're trying to use the Standard format strings to acheive what you're after, however you're going to need to look at the Custom Numeric Format Strings (MSDN). These should enable to set things up exactly as you require.

Answer 4

Something like this

 .toString("#,###");