CODEWITHSUNDEEP
javaregex
user1020788
user1020788

Reputation: 151

Regex for parsing floats

I am looking to make a regex that will parse all floats in a given string. The thing is I need to ignore a special case; floats that are preceded by a /

The regex I currently have works okay, but it doesn't ignore the full float just the number after the /

(?<!/)[-]?[0-9]*\.?[0-9]+

Below are a few samples:

Thanks in advance

Upvotes: 2

Views: 164

Answers (2)

hwnd
hwnd

Reputation: 70732

The Lookbehind excluding (/) is not enough here, it's tricky but you need to exclude (0-9, ., -) along with (/) followed by a space in order to match the floats you specified.

(?<![0-9/.-]|/ )-?[0-9]*\.?[0-9]+

Live Demo

Another way to grab what you want would be to match the context you don't want. After matching the unwanted context, place what you want matched inside a capturing group and access that group for your matches.

/\s*\S+|(-?[0-9]*\.?[0-9]+)

Live Demo

Upvotes: 2

MattSizzle
MattSizzle

Reputation: 3175

This is a rather good Regex question in my opinion. Assuming you want to do a replace on any float number that IS NOT preceded by a / the following will work. This is the opposite of what your original regex did, but it is probably easier to implement and is easier to read.

Regex

(?:[a-z]*|\/.*)

Regex101

Test Data

1.25 some text /1.10 some more text
1 some different text
1.25 some text .012 some more text
-1.25 some text
/1.25
/you missed one 1.10

My Java is rusty, but an example usage would be:

str = str.replaceAll("(?:[a-z]*|\/.*)", "");

Upvotes: 0

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