Question

I never tried regex before today, and I like it so far, but I’m lost on some things.

I have a string that looks like this:

Type OtherType ThirdType - SubType AnotherSubType QuiteTheType

I want two regex, both care about the ‘-‘ character.
First I want all words before that character, then all words after it. I will be using Ruby’s gsub to turn them into an array of strings, two arrays, which is why I need two regex expressions.

So far I have this: ([a-zA-z]{1,}) (?=-) but that only gets me the word right before the dash, I.E. ThirdType.
If I just use ([a-zA-z]{1,}) I get all words highlighted, but that includes the ones AFTER the - which I don’t want yet.

How can I get all occurrences of [a-zA-z]{1,} that happen before - but not necessarily IMMEDIATELY before it?

Answer 1

I don’t know exactly how Ruby’s regex implementation works, but the following regex in Perl should get you what you want:

/^([a-zA-z\s]+) \- ([a-zA-Z\s]+)$/

For example:

perl -e '$_="Type OtherType ThirdType - SubType AnotherSubType QuiteTheType";
if(/^([a-zA-z\s]+) \- ([a-zA-Z\s]+)$/){print "$1\n";print "$2\n";}'

produces

Type OtherType ThirdType
SubType AnotherSubType QuiteTheType

ETA: To explain what’s going on, the initial ^ denotes the beginning of the line and the ending $ denotes the end of the line. So, ^([a-zA-Z\s]+) starts at the beginning and (greedily) matches all of the words from the beginning of the line up until the space before the dash (which is escaped by a backslash, since - is a reserved character in most regex implementations). Likewise with ([a-zA-Z\s]+)$.