I'm trying to match different variations of distance presentation which works pretty well for bigger values but fails on single digits

^(?:(?<distanceMeter>\d [,|.]?\d ?) ?\/? ?(?<distanceFemaleMeter>\d ?[,|.]?\d ?)?) ?-m ?(?<text>[\w\s] ) matches

• 2000/ 1,500-m row and
• 2000-m row

But it fails to match

• 10/ 5-m row
• 9-m row

I thought d always matches 1 or more digits, but its not working.

CodePudding user response：

In the pattern that you tried you use \d ? which matches at least 1 digits, and making it non greedy matches the least amount, but there still has to be at least a single digit.

Note that using (?:\d )? is the same as \d*, and using [\w\s] at the end can also match only whitespace chars (that can also match only newlines) You can use a space instead, as in the rest of the pattern you also match spaces.

Your examples should all match the digits at the start, and are followed by an optional / and digits part and then the -m part should be present followed by "text"

For that format, you can make the whole part with / and the digits optional.

^(?<distanceMeter>\d (?:[,.]\d )?)(?: ?\/ ?(?<distanceFemaleMeter>\d (?:[,.]\d )?))? ?-m ?(?<text>\w (?: \w )*)

• ^ Start of string
• (?<distanceMeter>\d (?:[,.]\d )?) Group distanceMeter, match 1 digits with an optional decimal part
• (?: Non capture group
  • ?\/ ? Match / between optional spaces
  • (?<distanceFemaleMeter>\d (?:[,.]\d )?) Group distanceFemaleMeter, match 1 digits with an optional decimal part
• )? Close the non capture group and make it optional
• ?-m ? Match -m between optional spaces
• (?<text>\w (?: \w )*) Group text, match 1 word chars and optionally repeat a space and 1 word chars

See a regex demo.

CodePudding user response：

After posting I actually figured out that creating a new group can handle this, so instead of \d ? using (?:\d )? works

^(?:(?<distanceMeter>\d [,|.]?(?:\d )?) ?\/? ?(?<distanceFemaleMeter>\d ?[,|.]?(?:\d )?)?) ?-m ?(?<text>[\w\s] )