Ruby Notes – Ch1 AppAcademy.io Coding Test

The following are my notes from the appacademy.io chapter 1 introduction to programming.

There are three types of data in Ruby:

  1. Numbers
  2. Booleans – True or false
  3. Strings – Words or phrases

Ruby is case sensitive

puts can be called methods in Ruby

Integers = Whole #s (ex 42)

Floats = Fractional #s (e.g. 3.14)

Never write commas when writing integers. They will change everything.

Notes on Division

Ruby does not divide into integers. It returns whole #s

puts (9.0/2) | #returns 4.5

puts (9.fdive(2)) | #returns 4.5

Modulo n%m -> returns the remainder from division

Defining Variables

ian_loves = “guitar, wifey, surfing”

Variables must:

  • consist of letters or/and #s
  • first character must be lowerCase
  • no spaces (separate words w/ _ )

Gets Method

The gets method allows you to ask users to define variables
puts("Type in your name, please.")
name=gets()
puts(name)

This would return whatever the user entered

Gets for Strings and Integers

Converting Strings and Integers

  • to_i = to integer
  • to_s = to string

The Chomp Method

chomp makes it so a line break doesn’t happen behind each gets command. It seems like it’s used most of the time. For example:

puts("Type your name, please.")
name = gets
name = name.chomp
puts ("Hello" + name)

use gets.chomp rather than reassigning the variables.

 

Important Note: Feeling good about all of this. I can write program files using Atom and execute the files using terminal.

I went through the Codecademy command line class which was a critical step in understanding how to navigate and execute programs using just typing. This makes it so I can at least pretend to be like the guy in Mr. Robot.

It was today, November 20th, 2015 (these notes were copied her later) that I actually wrote and executed my first computer program. It was a game that said hello.
puts("Hello. What is your name, please?")
name = gets
name = name.chomp
puts("Hi " + name + ", it's nice to meet you.")

Screen Shot 2015-12-06 at 2.11.28 PM

 

That’s it

If you’d like to continue to follow along with these notes, I continue the study in my notes in chapter 2.

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