the first word
Matches the first word. It finds the match anywhere inside the text. There is 1 capture group.
Pattern
/^\s*(\S+)/- Match scope
- anywhere inside the text
- Capture groups
- 1
- What it catches in the first example
- hello
Try it yourself
Type any text and the parts this expression catches are highlighted. It runs in your browser and is never sent anywhere.
hello world
hi
1 match
Examples that match
- hello world
- hi
Examples that do not match
- ""
Other expressions in this group
_([a-z])the letter that follows an underscore-([a-z])the letter that follows a hyphen(?:^|,)("(?:[^"]|"")*"|[^,]+)one comma-separated field^([^=]+)=(.*)$a name and value split by an equals sign(\S+)\s*$the last word\d+runs of digits inside a text\b\w+\beach word, one by one\[([^\]]*)\]what sits inside square bracketsHow 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 the first word?
^\s*(\S+).
Q. Which strings match?
Text like hello world matches; text like "" does not.
Q. Does the whole string have to match?
No. It finds the part anywhere inside the text. Add ^ and $ around it if you want a whole-string check.
Q. How do I use what it caught?
There is one capture group, so you can read them from match[1] onwards.