So i have this String:
val line = "Displaying elements 1 - 4 of 4 in total"
And i want to to parse the total amount: 4 in this case.
This is what i have try:
val line = "Displaying elements 1 - 4 of 4 in total"
val pattern = "\\d".r
println(pattern.findAllMatchIn(line))
The regex API in Scala only provides a method to get the first match (findFirstIn) or all matches (findAllIn), but not the last match. Most languages have a similar set of regex methods because to get the last regex match you may easily get all matches but only refer to the last one.
Same in Scala:
val line = "Displaying invoices 1 - 4 of 9 in total"
val pattern = """\d+""".r
println(pattern.findAllIn(line).toList.last)
// => 9
As an alternative, for the current scenario, you may also use
val line = "Displaying invoices 1 - 4 of 4 in total"
val pattern = """\d+(?=\s*in total)""".r
println(pattern.findFirstIn(line))
See IDEONE demo.
The \d+(?=\s*in total) pattern will find 1 or more digits (\d+) that are followed with 0+ whitespaces and in total substring (see the positive lookahead (?=\s*in total)).
You can let greed eat up the line until last number.
.*\b(\d+)
.* matches greedily any amount of any character until \b a word boundary(\d+) capture one or more \d digits by group(1)If you expect decimal number, add a lookbehind and modify to .*\b(?<![.,])(\d[\d.,]*)
line.split(' ')(6)'Some people, when confronted with a problem, think "I know, I'll use regular expressions.' Now they have two problems.'' - Jamie Zawinski