Regex to convert 2-digitno to 3-digitno

Question

I had a requirement where in my file I had to replace all 2-digitno occurrences to corresponding 3-digitno.

For example:

48 should be replaced by 048.
02 should be replaces by 002.

Till now I am able to identify 2 digit nos in my document with expression:

^[0-9]{2}$

But I am not able to figure out how to append 0 to no. Kindly help me in writing regular expression for this.

possible duplicate of [Reference - What does this regex mean?](http://stackoverflow.com/questions/22937618/reference-what-does-this-regex-mean) — Reinstate Monica -- notmaynard, Aug 13 '15 at 14:08
Hi Gary, since I have a long document, I am simply using replace feature of Notepad++ application on Windows7 — NANCY, Aug 13 '15 at 14:58
Till now I am able to identify 2 digit nos in my document with expression : ^[0-9]{2}$ ..........But I am not able to figure out how to append 0 to no. — NANCY, Aug 13 '15 at 15:15

score 2 · Answer 1 · answered Aug 13 '15 at 14:01

2

You can simply replace the result of following regex :

/\b(\d\d)\b/g

to :

/0\1/

or for capturing the group in some regex engines use $1

answered Aug 13 '15 at 14:01

kasravnd

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Kasramvd, I am using replace feature of Notepad++ application – NANCY Aug 13 '15 at 15:03

score 1 · Accepted Answer · answered Aug 13 '15 at 21:24

1

Use this in the Search and Replace dialog:

Find what: \b\d{2}\b
Replace with: 0$0

Note that ^[0-9]{2}$ means match 2 digits from the beginning of the line till end. So, if you have several numbers and not equaling the whole line, your regex would not work.

\b is a word boundary, and makes sure there is a letter, digit or an underscore before/after the word.

answered Aug 13 '15 at 21:24

Wiktor Stribiżew

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This worked.understood usage of \b. Wanted to ask how regex 0$0 coverted no by appending it with 0. – NANCY Aug 14 '15 at 06:08
`$0` is a backreference to the whole text matched by the regex pattern. It will hold 2 digits. – Wiktor Stribiżew Aug 14 '15 at 06:22

Regex to convert 2-digitno to 3-digitno

2 Answers2