How to create leading zeros?

Question

protected void Page_Load(object sender, EventArgs e)
{
    lab.Text = FormatTelephoneNumber("0034523");
}

public static string FormatTelephoneNumber(string value)
{
   value = new System.Text.RegularExpressions.Regex(@"\D").Replace(value, string.Empty);
   return Convert.ToInt64(value).ToString(" #- ###-###");

}

Gives Output:

34-523

But I need output:

0-034-523

0034523 would Become 0-034-523 and 00345 would become 0-034-5 (no extra valeue or 0- 000-345)

use [PadLeft(7, '0')](http://msdn.microsoft.com/en-us/library/system.string.padleft%28v=vs.110%29.aspx) to add `0` characters to your string before formatting — Mivaweb, Dec 19 '14 at 11:02
Would you want inputs of "034523", "34523", "0034523" to give different results? If so, you should definitely *not* be converting them to integers. — Jon Skeet, Dec 19 '14 at 11:04
return Convert.ToInt64(value).ToString(" #- ###-###"); this line use 0 value not converted. so how to value return. please give example. — Aravindh, Dec 19 '14 at 11:18

score 4 · Answer 1 · edited Dec 19 '14 at 11:13

4

According to MSDN, you could use 0 instead of #

value.ToString("0- 000-000")

edited Dec 19 '14 at 11:13

Patrick Hofman

153,850
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answered Dec 19 '14 at 11:02

HoXa

153
9

2

Maybe add some code so that the person does not need to go elsewhere. – Anthony Horne Dec 19 '14 at 11:03
0034523 would Become 0-034-523 and 00345 would become 0-034-5 (no extra valeue or 0- 000-345) Please Help me any one – Aravindh Dec 19 '14 at 11:07
return Convert.ToInt64(value).ToString(" #- ###-###"); this line use 0 value not converted. so how to value return. please give example – Aravindh Dec 19 '14 at 11:19

score 4 · Answer 2 · edited Dec 19 '14 at 11:13

4

You should not convert it to int. Perform the regex on the string itself. Converting to int will ignore the leading 0's.

edited Dec 19 '14 at 11:13

Patrick Hofman

153,850
22
249
325

answered Dec 19 '14 at 11:03

Krishnandu Sarkar

494
1
6
21

Patrick Hofman · Answer 3 · 2014-12-19T11:16:37.823

3

Use 0- 000-000 as format instead.

To get the additional requirement for the format, use two formats:

int val = Convert.ToInt32(value);

if (val < 1000)
{
    return val.ToString("0-000-0");
}
else
{
    return val.ToString("0-000-000");
}

The 0 is used to indicate padding.

According to MSDN:

Replaces the zero with the corresponding digit if one is present; otherwise, zero appears in the result string.

edited Dec 19 '14 at 11:16

answered Dec 19 '14 at 11:03

Patrick Hofman

153,850
22
249
325

How to create leading zeros?

3 Answers3