Mask to format int 1, 10, 100, to string "001", "010", "100"

Question

How do I apply a mask to a string aiming to format the output text in the following fashion (at most 2 leading zeros):

int a = 1, b = 10, c = 100;
string aF = LeadingZeroFormat(a), bF = LeadingZeroFormat(b), cF = LeadingZeroFormat(c);
Console.Writeline("{0}, {1}, {2}", aF, bF, cF); // "001, 010, 100"

What is the most elegant solution?

Thanks in advance.

http://stackoverflow.com/questions/3122677/add-zero-padding-to-a-string — murgatroid99, May 15 '12 at 17:47
possible duplicate of [Pad with leading zeros](http://stackoverflow.com/questions/3459610/pad-with-leading-zeros) — Kendall Frey, May 15 '12 at 17:48

score 48 · Accepted Answer · answered May 15 '12 at 17:46

48

You can use Int32.ToString("000") to format an integer in this manner. For details, see Custom Numeric Format Strings and Int32.ToString:

string one = a.ToString("000"); // 001
string two = b.ToString("000"); // 010

answered May 15 '12 at 17:46

Reed Copsey

554,122
78
1,158
1,373

1

Thanks..saved a lot of my time – cosmoloc Oct 14 '14 at 13:26

score 17 · Answer 2 · answered May 15 '12 at 17:47

17

As well as Reed's suggestion, you can do it directly in your compound format string:

int a = 1, b = 10, c = 100;
Console.WriteLine("{0:000}, {1:000}, {2:000}", a, b, c); // "001, 010, 100"

answered May 15 '12 at 17:47

Jon Skeet

1,421,763
867
9,128
9,194

score 3 · Answer 3 · answered May 15 '12 at 17:49

To display the integer as a decimal value, call its ToString(String) method, and pass the string "Dn" as the value of the format parameter, where n represents the minimum length of the string.

int i = 10;
Console.WriteLine(i.ToString("D3"));

Also check How to: Pad a Number with Leading Zeros

Mask to format int 1, 10, 100, to string "001", "010", "100"

3 Answers3