Regex for a semantic version
Escaped dots, and what happens when you forget to escape them.
/^\d+\.\d+\.\d+$/
Match a whole string consisting of one or more of a digit, then ".", then one or more of a digit, then ".", then one or more of a digit.
What to check
Note
Anchors match string ends, not line ends
Without the m flag, ^ and $ match only the very start and end of the input — not the start and end of each line. On multi-line input this is often not what was intended.
Fix: Add the m flag if the pattern should apply per line.
Step by step
^Anchor to the start of the input.
\d+Match one or more of a digit.
.Match ".".
\d+Match one or more of a digit.
.Match ".".
\d+Match one or more of a digit.
$Anchor to the end of the input.
Details
- Capture groups
- None
- Flags
- None set
Check your own pattern
Paste one on the home page, or call the API or MCP server. This page is also available as markdown.