Programming

Ruby


Ruby is a general purpose interpreted object oriented language popular for building websites (search Google for “Ruby on Rails”).  It is similar to Python and Perl.

Download software: http://rubyinstaller.org (Windows)

Cost: Free

Instructions to setup software: See Ruby installer at http://rubyinstaller.org

Hardware requirements: PC, Mac

Operating systems supported: Win, Mac, Linux

Difficulty level: 3 out of 5


TRY IT!

1. Copy this text, paste into notepad (or some other text editor) and save as “TempF_to_C.rb”


def getFTemp
	print "Enter Temperature Degrees F :"
	tempF = gets()
	tempC = (tempF.to_f - 32)*5/9
	puts "Temperature Degrees C: #{tempC}"
	return tempF
end

def useTemp (temp)
	if (temp.to_f > 100)
		print "Hydrate!!"
	end
	if (temp.to_f <32)
		print "Pack Long Underwear!!"
	end
end

begin
	Ftemp = getFTemp
	useTemp(Ftemp)
end

2. From the command prompt, type: “Ruby200\bin\ruby.exe TempF_to_C.rb”

Here is a sample session:

ruby


ABOUT THE PROGRAM — A WALK THROUGH

The program starts at the “begin” near the bottom.

It uses the “getFTemp” method to prompt the user and convert the temperature to Degrees C.

It then uses the “useTemp” method to decide which message to display.


TRY THIS

1. Modify “useTemp” to display a message for temperatures between 32 and 100.

2. Change the messages that are displayed.

3. Change the temperatures that trip the message displays.


LEARN MORE

Programming Ruby – an excellent on line book

Ruby in Twenty Minutes


RESOURCES, TIPS, TRICKS AND HINTS

http://www.rubycentral.com

http://www.ruby-lang.org

Write a comment about “Ruby”

Nickname:

Type your comment:

  • 1. Safety. Do the following:
      a. Show your counselor your current, up-to-date Cyber Chip.
      b. Discuss first aid and prevention for the types of injuries or illnesses that could occur during programming activities, including repetitive stress injuries and eyestrain.

    2. History. Do the following:
      a. Give a brief history of programming, including at least three milestones related to the advancement or development of programming.
      b. Describe the evolution of programming methods and how they have improved over time.

    3. General knowledge. Do the following:
      a. Create a list of 10 popular programming languages in use today and describe which industry or industries they are primarily used in and why.
      b. Describe three different programmed devices you rely on every day.

    4. Intellectual property. Do the following:
      a. Explain how software patents and copyrights protect a programmer.
      b. Describe the difference between licensing and owning software.
      c. Describe the differences between freeware, open source, and commercial software, and why it is important to respect the terms of use of each.

    5. Projects. Do the following:
      a. With your counselor’s approval, choose a sample program. Then, as a minimum, modify the code or add a function or subprogram to it. Debug and demonstrate the modified program to your counselor.
      b. With your counselor’s approval, choose a second programming language and development environment, different from those used for requirement 5a and in a different industry from 5a. Then write, debug, and demonstrate a functioning program to your counselor, using that language and environment.
      c. With your counselor’s approval, choose a third programming language and development environment, different from those used for requirements 5a and 5b and in a different industry from 5a or 5b. Then write, debug, and demonstrate a functioning program to your counselor, using that language and environment.
      d. Explain how the programs you wrote for requirements 5a, 5b, and 5c process inputs, how they make decisions based on those inputs, and how they provide outputs based on the decision making.

    6. Careers. Find out about three career opportunities in programming. Pick one and find out the education, training, and experience required. Discuss this with your counselor and explain why this career might be of interest to you.

  • Earning the Cyber Chip can help you learn how to stay safe while you are online and using social networks or the latest electronic gadgets.

    Topics include cell phone use, texting, blogging, gaming, cyberbullying, and identity theft. Find out more about the Cyber Chip at www.scouting.org/cyberchip.