How to Prefix '0' (zero) to integer value

Question

I have a situation where I need to prefix a zero to an integer. Initially I have string which has 12 chars, first 7 are alphabets and 5 are numeric values. The generated string some times have a zero at starting position of numeric values. for example ABCDEF*0*1234, and my scenario is to generate a range of strings from the generated string. Suppose I want to generate a range (assume 3 in number), so it would be ABCDEF01235, ABCDEF01236, ABCDEF01237.

When I try to convert a string which has a 0 (as shown above) to int, it returns only 1234. Is there any way to do this, without truncating zero?

`1234 == 01234` for integers, `0` will be ignored. For displaying purpose you can use string format to pad a leading `0` — Habib, Nov 21 '12 at 07:35
Possible duplicate [How can I format a number into a string with leading zeros?](http://stackoverflow.com/questions/5418324/c-sharp-how-can-i-format-a-number-into-a-string-with-leading-zeros) — horgh, Nov 21 '12 at 07:53

score 8 · Accepted Answer · edited Jun 22 '18 at 07:59

8

You can use PadLeft to expand a given string to a given total length:

int num = 1234;
Console.WriteLine(num.ToString().PadLeft(5, '0'));  // "01234"

edited Jun 22 '18 at 07:59

prime23

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answered Nov 21 '12 at 07:37

McGarnagle

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We can do that using PadLeft, my question is can we convert to int when a string has prefixed with zero. It seems to be not possible by looking at the comments below. – Sham Nov 21 '12 at 08:42
@sham leading zeros make no sense for an integer -- can't you generate your range of numbers, then pad after converting back to a string? – McGarnagle Nov 21 '12 at 08:45
Thanks for your input. I guess that would be the only option left out. – Sham Nov 21 '12 at 08:55

score 6 · Answer 2 · answered Apr 30 '15 at 13:30

6

 int num = 1234;
 Console.WriteLine(num.ToString("D5"));  // "01234"

answered Apr 30 '15 at 13:30

Simon Hughes

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score 0 · Answer 3 · answered Nov 21 '12 at 07:37

0

No with int.

You have to use string to concatenate the parsed number and the 0

answered Nov 21 '12 at 07:37

Gianni B.

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score 0 · Answer 4 · answered Jun 28 '22 at 12:38

0

int num = 1234;
Console.WriteLine($"{num:d5}");

answered Jun 28 '22 at 12:38

Koycho Drekov

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score -1 · Answer 5 · answered Nov 21 '12 at 07:56

-1

I think you can use string.Format

    int num = 1234;
    Console.WriteLine(string.Format("0{0}", num));

answered Nov 21 '12 at 07:56

leon_ALiang

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How to Prefix '0' (zero) to integer value

5 Answers5