Console not ready ruby sublime text file - ruby

Question

I'm new to programming. Just about to start learning Ruby. I already took a console class, but I am stuck here.
I'm using a mac 10.6.8. I have done a quick 1+2 in the sublime text editor. I saved it. I went over to my console typed irb and then typed ruby example.rb. I have read elsewhere here that typing require './example' would help....it didn't. I am getting the following
NameError: undefined local variable or method `example' for main:Object
from (irb):2
from /usr/local/rvm/rubies/ruby-1.9.3-p392/bin/irb:16:in `<main>'
I don't understand what I am doing wrong. Thank you for your help. I really appreciate it.
-L

Answer 1

I would do as below:
kirti#kirti-Aspire-5733Z:~$ irb
2.0.0p0 :001 > require 'fileutils'
=> true
2.0.0p0 :002 > FileUtils.pwd
=> "/home/kirti"
2.0.0p0 :003 > FileUtils.cd "/home/kirti/ruby"
=> nil
2.0.0p0 :004 > load "./SO.rb"
3
=> true
2.0.0p0 :005 > require "./SO.rb"
3
=> true
My SO.rb file contains the below line :
puts 1+2

Answer 2

May be you wanna give a try.
Step 1: Navigate to your project/file folder by using command "cd folder_name/folder_location"
Step 2: load './example.rb'
For better solution you may wanna define some function inside example.rb
Like:
def sum
1 + 2
end
And to get the output enter sum in irb after loading the example.rb file.

Answer 3

irb is the interactive ruby shell. Within the shell, everything you type is interpreted as Ruby code, not bash commands. So, for example:
bash> puts 1 + 2
# command not found: puts
# this happens because you're not in a Ruby shell
bash> irb
# now you're in a Ruby shell
irb> puts 1 + 2
# 3
If you wrote some code in example.rb, you have two options:
From the bash shell, run ruby example.rb (from the same directory where your example.rb file is saved.
From the irb console, you can require 'example', which will load the contents of example.rb into your interpreter. In this case, it will immediately execute the Ruby code. If you wrapped the contents of example.rb in a class, it would load the class, but not execute code within it until you instantiated/called it.
Hopefully that helps!

Answer 4

My guess is that you are typing (into irb):
require example.rb
When you need to type:
require './example.rb'
The first tells ruby: "require what is in a variable called example". Because you did not define a variable called example, it results in the no variable or method error.
The second tells ruby: "require a string './example.rb'". Since the require method essentially knows how to find the file name passed as a string and evaluate the file, you'll get the right output
By the way, for this example, example.rb needs to be in the same directory. If example.rb is in another directory, you'll need to use the full path (I won't expand on it here) to source it.
You'll also notice that the output will look something like this:
3
=> true
This is because the file was evaluated (executing the code: puts 1+2) and the require method returns true to indicate it evaluated the file.
If you require the file again, you'll get false because the file is already loaded.