From: "Bartosz Dziewoński" Date: 2011-08-15T02:49:54+09:00 Subject: Re: Getting information from keyboard The square brackets are there simply to indicate this is an optional argument. You can sometimes even come across methods that have nested brackets - e.g. something( arg1 [, arg2 [, arg3 ]] ) - this simply means that all arguments except the first are optional. This is a quite widely used convention, also present in, for example, PHP documentation. -- Matma Rex 2011/8/14 amir e. : > Bartosz Dziewoński , I am very thankful from you. but I have another > question I don't understand exactly what is the [,opt] and how can I use > that ? > thanks > > -- > Posted via http://www.ruby-forum.com/. >