RegEx match exactly 4 digits

Question

Ok, i have a regex pattern like this /^([SW])\w+([0-9]{4})$/

This pattern should match a string like SW0001 with SW-Prefix and 4 digits.

I thougth [0-9]{4} would do the job, but it also matches strings with 5 digits and so on.

Any suggestions on how to get this to work to only match strings with SW and 4 digits?

Add the `$` anchor. `/^SW\d{4}$/`. It's because of the `\w+` where `\w+` match one or more alphanumeric characters. — Tushar, Mar 08 '17 at 15:00
`\w+` matches digits as well. Did you mean to use `/^([SW])[a-zA-Z]*([0-9]{4})$/`? — Wiktor Stribiżew, Mar 08 '17 at 15:04

score 75 · Accepted Answer · answered Mar 08 '17 at 15:04

Let's see what the regex /^([SW])\w+([0-9]{4})$/ match

This match more than just SW0001.

Use the below regex.

/^SW\d{4}$/

This regex will match string that starts with SW followed by exactly four digits.

score 30 · Answer 2 · answered Mar 08 '17 at 15:03

30

in regex,

so if you want to match "SW" + exactly 4 digits you need

^SW[0-9]{4}$

answered Mar 08 '17 at 15:03

Jerome WAGNER

score 5 · Answer 3 · edited Jun 23 '22 at 10:39

5

you can use this code in regex

^\d{4}$

edited Jun 23 '22 at 10:39

Wiktor Stribiżew

answered Apr 06 '22 at 07:02

sinasho

score 0 · Answer 4 · answered Jun 12 '21 at 21:29

0

If you want to get into regex and match 4 numbers... You can backslash the periods too.

get-childitem | where name -match 'journal.\d{4}.txt'

answered Jun 12 '21 at 21:29

js2010

4 Answers4