Open In App
Related Articles

Ruby Search and Replace

Improve
Improve
Improve
Like Article
Like
Save Article
Save
Report issue
Report
sub and gsub string methods that use regular expressions, and their in-place variants are sub! and gsub!. The sub & sub! replaces the first occurrence of the pattern and gsub & gsub! replaces all occurrences. All of these methods perform a search-and-replace operation using a Regexp pattern. sub! and gsub! modify the string on which they are called whereas the sub and gsub returns a new string, leaving the original unmodified. Below is the example to understand it better. Example :
# Ruby program of sub and gsub method in a string
  
roll = "2004-959-559 # This is Roll Number"
  
# Delete Ruby-style comments
roll = roll.sub!(/#.*$/, "")   
puts "Roll Num : #{roll}"
  
# Remove anything other than digits
roll = roll.gsub!(/\D/, "")    
puts "Roll Num : #{roll}"

                    
Output :
Roll Num : 2004-959-559 
Roll Num : 2004959559
In above example, we are using sub! and gsub!. here sub! replace first occurrence of the pattern and gsub! replaces all occurrences. Example :
# Ruby program of sub and gsub method
text = "geeks for geeks, is a computer science portal"
  
# Change "rails" to "Rails" throughout
text.gsub!("geeks", "Geeks")
  
# Capitalize the word "Rails" throughout
text.gsub!(/\bgeeks\b/, "Geeks")
puts "#{text}"

                    
Output :
Geeks for Geeks, is a computer science portal
The gsub! method too can be used with a regular expression.

Last Updated : 25 Sep, 2019
Like Article
Save Article
Previous
Next
Share your thoughts in the comments
Similar Reads