Alaa Afifi kamal

Faculty of computers and information cairo university

Vice head to social at fci student union

Participant at NYU Abu Dhabi Hackathon

Intern at imagine cup university (microsoft)

Social media member st scci

FR member at Fekra

alaa.kamal67@yahoo.com

Introduction to Ruby

Ruby

Ruby is a powerful, flexible programming language you can use in web/Internet development, to process text, to create games, and as part of the popular Ruby on Rails web framework. Ruby is:

High-level, meaning reading and writing Ruby is really easy—it looks a lot like regular English!

Interpreted, meaning you don't need a compiler to write and run Ruby. You can write it here at Codecademy or even on your own computer (many are shipped with the Ruby interpreter built in—we'll get to the interpreter later in this lesson).

Object-oriented, meaning it allows users to manipulate data structures called objects in order to build and execute programs. We'll learn more about objects later, but for now, all you need to know is everything in Ruby is an object.

Easy to use. Ruby was designed by Yukihiro Matsumoto (often just called "Matz") in 1995. Matz set out to design a language that emphasized human needs over those of the computer, which is why Ruby is so easy to pick up.

Ruby

Outline :

Data taypes(numbers,Booleans and string)

Operators

(Puts,print)

Strings

Single _line comments

Multi_line comments

Data types

Numbers is a data tybe at Ruby to define numbers just

My _num=25

Booleans is a data tybe at Ruby to define Booleans just

My_bool=true or false just

string is a data tybe at Ruby to define strings just

My_string=“Ruby”

operators

Addition(+) ,subtraction(-),multiplication(*),Division(/),Exponentiation(**) and

module(%)

Exponentiation(**) is used to get the power of the number

Ex: 2 x 2 x 2 =2**3=8 .

module(%) is used to get the remainder of division

Ex: 20%3= 2

How to write it as a code?

My_num=4+4

Output= 8

(Puts,print)

The print command just takes whatever you give it and prints it in the screen.

Puts it adds a new (blank) line after the things you want it to print

Ex: puts”Hello”

print”Ruby”

stringsLength:

if you want to get the legth of string do that

Ex: “Ruby”.length

output= 4

reverse:

this method help us to sort a list of values

Ex: “Ruby”.reverse

output= ybuR

Downcase and upcase methods convert a string ALL UPPER CASE

or lower case

to use upcase or downcase

EX: puts”ruby”.upcase

the output: RUBY

Ex: puts”RUBY”.downcase

the output: ruby

Single _line comments

A comment is a bit of text that Ruby won't try to run as code: it's just for

humans to read. Writing good comments not only clarifies your code for other

people who may read it, but helps remind you of what you were doing when

you wrote the code days, months, or even years earlier.

we use # to write a comment

Ex: “ I love Ruby”.length # this line return the length

Multi_line comments

You can write a comment that spans multiple lines by starting

each line with a # , but there's an easier way.

if you start with =begin and end with =end ,

everything between those two expressions will be a comment.

Ex:

=begin

I love ruby

it’s nice

=end

Thank you

Copyrights to:Alaa Afifi