From: Nick Brown <ruby-forum.com@...>
Date: 2008-08-21T05:25:14+09:00
Subject: Re: unintuitive language feature (exclamation functions)

F. Senault wrote:
> Please provide some code to demonstrate this.

#!/usr/bin/env ruby

require 'sqlite3'
db = SQLite3::Database.new('test.sqlite')
db.execute ('drop table if exists example') # clean up incase of 
multiple runs
db.execute('create table example (aval)')

require 'cgi'
cgi = CGI.new('html4')

a = cgi['a']

a.sub!(/hi/, 'bye')
# to see expected behavior, replace the above with: a = a.sub(/hi/, 
'bye')

puts "Inserting value a=#{a} into the database.\n"
sql = "insert into example (aval) values (?)"
db.execute(sql, a)

sql = "select aval from example"
val = db.get_first_value(sql)
puts "What was actually inserted into the database: #{val}\n"


########---------- end of code

To run this, type "a=hi"[enter][ctrl-d] to simulate the behavior of a 
cgi session. You will get the output:

Inserting value a=bye into the database.
What was actually inserted into the database: hi

Since other responders seem to think I expect sub to behave the same as 
sub!, I don't. I expect str.sub! to modify str, and I expect str.sub to 
return a modified copy of the str. This is not the same behavior.
-- 
Posted via http://www.ruby-forum.com/.