Question

How to split the string from the second occurrence of the character

str = "20050451100_9253629709-2-2"

I need the output 
["20110504151100_9253629709-2", "2"]

Answer 1

You could use regular expression matching:

str = "20050451100_9253629709-2-2"
m = str.match /(.+)-(\d+)/
[m[1], m[2]]  # => ["20050451100_9253629709-2", "2"]

The regular expression matches “anything” followed by a dash followed by number digits.