a name and value split by an equals sign
Matches a name and value split by an equals sign. It is anchored at both ends, so the whole string has to match. There are 2 capture groups.
Pattern
/^([^=]+)=(.*)$/m- Match scope
- the whole string
- Capture groups
- 2
- Flags
- m · per line
- What it catches in the first example
- KEY=value
Try it yourself
Type any text and the parts this expression catches are highlighted. It runs in your browser and is never sent anywhere.
KEY=value
1 match
Examples that match
- KEY=value
- a=
Examples that do not match
- novalue
- =only
Other expressions in this group
(?<=[a-z0-9])(?=[A-Z])the seam between words in camelCase_([a-z])the letter that follows an underscore-([a-z])the letter that follows a hyphen(?:^|,)("(?:[^"]|"")*"|[^,]+)one comma-separated field^\s*(\S+)the first word(\S+)\s*$the last word\d+runs of digits inside a text\b\w+\beach word, one by oneHow to read this
- With ^ and $ around it, the whole string must match; without them the match can sit anywhere. Always anchor an expression you use for validation.
- Round brackets ( ) capture what they wrap. When you only need grouping, write (?: ) so the numbering of later groups does not shift.
- Every expression here is checked against its examples. Even so, "looks like an email" and "is a real inbox" remain different questions.
- Nested open-ended repeats such as (a+)+ can blow up on certain inputs. Look for that shape before pasting someone else’s expression into your code.
Frequently asked questions
Q. What is the regex for a name and value split by an equals sign?
^([^=]+)=(.*)$, with the m flag.
Q. Which strings match?
Text like KEY=value matches; text like novalue does not.
Q. Does the whole string have to match?
Yes. It is wrapped in ^ and $, so nothing but a full match passes.
Q. How do I use what it caught?
There are 2 capture groups, so you can read them from match[1] onwards.