Question

Let’s say I have the following string:

here is some text in a sentence 55 and
some other text still in the same
sentence

There are two instances of the substring sentence in the string. How can I find the instance that is closest to the substring 55?

I am using Ruby 1.9.2

Answer 1

Split the string on the marker:

first, last = str.split("55")

Distance from the second is simply via #index:

last_dist = last.index("sentence")

Distance from the first is slightly funkier:

first_dist = first.reverse.index("sentence".reverse")

Compare:

result = first_dist < last_dist ? :first : :last