Description of a Regular Expression

Regular expressions are complex. There are many references available, on the Internet, and elsewhere, to help you understand them more fully.

Expression: `(^|[^-.\d])(\d+(?:\.\d+)?)-(?=[^-.\d]|$)`

A "capture group" is a regular expression surrounded by parentheses that is remembered as a numbered variable for use in the replacement.

Detail of Expression	Description
`(^\|[^-.\d])` A numbered capture group (Becomes $1 in the replacement)	Select from 2 alternatives: Beginning of line or string Any character that is not in this class: `[-.\d]` (minus, decimal, or digit)
`(\d+(?:\.\d+)?)` A numbered capture group (Becomes $2 in the replacement)	`\d+(?:\.\d+)?` Any digit, one or more repetitions Match expression but don't capture it. `[\.\d+]`, zero or one repetitions `\.\d+` Any digit, one or more repetitions
`-`	(Match on trailing minus)
`([^-.\d]\|$)` Match a suffix but exclude it from the capture.	Select from 2 alternatives: Any character that is not in this class: `[-.\d]` (minus, decimal, or digit) End of line or string

This translates a string like "123.45-" to "-123.45".