举例初步讲解Ruby中的正则表达式

#!/usr/bin/ruby

line1 = "Cats are smarter than dogs";
line2 = "Dogs also like meat";

if ( line1 =~ /Cats(.*)/ )
 puts "Line1 starts with Cats"
end
if ( line2 =~ /Cats(.*)/ )
 puts "Line2 starts with Dogs"
end

Line1 starts with Cats

# Following matches a single slash character, no escape required
%r|/|        

# Flag characters are allowed with this syntax, too
%r[</(.*)>]i 

#!/usr/bin/ruby

phone = "2004-959-559 #This is Phone Number"

# Delete Ruby-style comments
phone = phone.sub!(/#.*$/, "")  
puts "Phone Num : #{phone}"

# Remove anything other than digits
phone = phone.gsub!(/\D/, "")  
puts "Phone Num : #{phone}"

Phone Num : 2004-959-559
Phone Num : 2004959559

#!/usr/bin/ruby

text = "rails are rails, really good Ruby on Rails"

# Change "rails" to "Rails" throughout
text.gsub!("rails", "Rails")

# Capitalize the word "Rails" throughout
text.gsub!(/\brails\b/, "Rails")

puts "#{text}"

Rails are Rails, really good Ruby on Rails