×

Ruby Tutorial

• Ruby Home
• Ruby Overview
• Ruby Environment Setup
• Ruby vs Python

Ruby Basics

• Ruby Syntax
• Ruby Comments
• Ruby Variables
• Ruby Operators
• Ruby Blocks
• Ruby Check Data Type

Ruby Control Statements

• Ruby Conditional Statements
• Ruby Loops
• Ruby While Loop
• Ruby For Loop
• Ruby Do...While Loop
• Ruby Until Loop
• Ruby Nested For Loop
• Ruby Nested While Loop
• Ruby Nested Do...While Loop
• Ruby Nested Until Loop
• Ruby Break Statement
• Ruby Next Statement
• Ruby Redo and Retry
• Ruby Ranges

Ruby Methods

• Ruby Methods

Ruby Classes and Methods

• Ruby Private Classes
• Ruby Frozen Objects
• Ruby Access Control
• Ruby Singleton Methods
• Ruby Polymorphism
• Ruby Encapsulation

Ruby Arrays

• Ruby Arrays
• Creating Array with Array.[](*args)
• Creating Array with Array.new(size, obj)
• Creating Array with Array.new(Array_object)
• Creating Array with Array.new(size){|index|}
• Creating Array with & Operator
• Creating Array with * Operator
• Creating Array with + Operator
• Creating Array with - Operator
• Accessing Array with Array.at() Method
• Accessing Array with Array.fetch() Method
• Accessing Array with Array.take() and Array.drop() Methods
• Accessing First/Last Element with Array.first and Array.last
• Deleting with Array.pop and Array.shift Methods
• Removing with Array.delete() and Array.delete_at()
• Removing with Array.compact and Array.uniq
• Finding Array Length
• Adding with << Operator
• Array Element Assignment (index)
• Array Element Assignment (start, length)
• Array Identity Check
• Comparing Arrays
• Creating 2D Arrays
• Ruby Array Methods

Ruby Sets

• Ruby Set
• Ruby Set Comparison
• Ruby Set disjoint? Method
• Ruby Set intersect? Method
• Ruby Set delete_if() & keep_if()
• Ruby Set Print Elements
• Ruby Set Length
• Ruby Set Element Presence
• Ruby Set Join Elements
• Ruby Set Common Elements
• Ruby Set Difference
• Ruby Set Merge
• Ruby Set Empty Check
• Ruby Set Delete/Replace Element

Ruby Strings

• Ruby Strings
• Ruby String Creation
• Ruby String Append
• Ruby String Concatenation
• Ruby String Concatenation (+)
• Ruby concat() Method
• Ruby chomp Method
• Ruby Regular Expressions
• Ruby to_s Method

Ruby Classes & Objects

• Ruby OOP
• Ruby Classes
• Ruby Objects
• Ruby Constructors
• Ruby Base Class Constructor
• Ruby Inheritance
• Ruby Method Overriding

Ruby Hash

• Ruby Hashes
• Ruby Hash Creation
• Ruby Hash < Operator
• Ruby Hash <= Operator
• Ruby Hash == Operator
• Ruby Hash > Operator
• Ruby Hash >= Operator

Ruby Tools

• Ruby Gems
• Ruby Debugger

Ruby Functions

• Ruby Procs
• Ruby Lambdas
• Lambdas vs Procs
• Splat Arguments

Ruby Built-in Functions

• Ruby alias vs alias_method
• Ruby at() Function
• Ruby clear() Function
• Ruby assoc() Function
• Ruby push() Function
• Ruby pop() Function
• Ruby reverse() Function
• Ruby reverse! Function
• Ruby concat() Function
• Ruby to_s() Function

Misc.

• Ruby Date & Time
• Ruby Threads
• Ruby Multithreading
• Ruby Modules
• Ruby Mixins
• Ruby Exception Handling
• Ruby Raise Exceptions
• Ruby Exception Class Methods
• Ruby CGI Programming
• Ruby Socket Programming
• Ruby Database Access
• Ruby Sending Email
• Ruby Wait
• Ruby Custom Error Logger

Ruby Programs

• Basic Programs
• if/else Programs
• case Statement Programs
• Looping Programs
• Classes & Objects Programs
• User-defined Functions Programs
• Blocks Programs
• Modules and Mixins Programs
• Strings Programs
• Arrays Programs
• Constructors/Destructors, Inheritance Programs
• Date and Time Programs
• Set Programs
• File Handling Programs
• Threading Programs
• Hashes Programs
• Directories Programs

# Ruby program to find the 
# area of the circle

print "Enter radius: "
radius = gets.chomp.to_i  

area = 3.14 * radius * radius;

print "Area of circle: ",area

Enter radius: 1.2
Area of circle: 3.14