Java regex for finding combo of { and number

Question

I have a file with following information

Hi my {4 name is {4: Jeremy I {4: work in {4 Texas My job is {3 very {0 hard, I work until 4

I need to match all {4 values in this text, so I tried to write following regex: [\{4^:]

But when I try this on a regex tester, it matches all occurances of {, 4 and : but I only want the combination of {4 without a : in it.

What am I doing wrong?

All 4 occurrences? If you need to match `{4` not followed with `:`, use `String res = s.replaceAll("\\{4(?!:)", "newValue");`. If you need to replace all `{4`, just use `.replace("{4", "NEW_VALUE")` - no need for a regex. — Wiktor Stribiżew, May 24 '17 at 06:27
what do you mean ***...to match all {4***, you dont need regex for that... — ΦXocę 웃 Пepeúpa ツ, May 24 '17 at 06:27

Raman Sahasi · Accepted Answer · 2017-05-24T06:38:43.203

1

Use negative lookahead to remove {4 which are followed by :. Also remove square brackets as they will match all of the results individually.

{4(?!:)

{4 matches the characters {4 literally
(?!:) is negative lookahead which means look for {4 which are not followed by :

edited May 24 '17 at 06:38

answered May 24 '17 at 06:32

Raman Sahasi

1 Answers1