Scala Tutorial

• Introduction to Scala
• Setting up the environment in Scala
• How to install Scala in Linux?
• How to install Scala in Windows?
• What makes Scala scalable?
• Hello World in Scala
• Scala | Uniform Access Principle
• Scala vs Java
• Python vs Scala
• Difference between Kotlin and Scala
• Scala | REPL

Basics

• Scala Keywords
• Scala Identifiers
• Data Types in Scala
• Variables in Scala
• Scala Console | println, printf and readLine
• Scala Identifiers
• Scala | Pattern Matching
• Comments In Scala
• Command Line Argument in Scala
• Enumeration in Scala
• Scope of Variables In Scala
• Scala | Ranges

Control Statements

• Scala | Decision Making
• Scala | Loops(while, do..while, for, nested loops)
• For Loop in Scala
• while and do while Loop in Scala
• Break statement in Scala
• Scala | Literals
• Scala | yield Keyword
• Scala | Type Inference

OOP Concepts

• Class and Object in Scala
• Inner class in Scala
• Inheritance in Scala
• Operators in Scala
• Operators Precedence in Scala
• Abstract Classes in Scala
• Singleton and Companion Objects
• Generic Classes in Scala
• Access Modifiers in Scala
• Scala Constructors
• Scala | Primary Constructor
• Scala | Auxiliary Constructor
• Calling A Super Class Constructor in Scala
• Extending a Class in Scala
• Scala | Case Class and Case Object
• Scala | Polymorphism
• Value classes
• Scala | Field Overriding
• Scala | Abstract Type members
• Type Casting in Scala
• Object Casting in Scala
• Object Equality in Scala
• Scala | Multithreading
• Scala | Final
• Scala this keyword
• Scala | Controlling visibility of constructor fields

Parameterized - Type

• Scala Type Hierarchy
• Scala | Lower Bound
• Scala | Upper bound
• Scala | Variances
• Scala | Null, null, Nil, Nothing, None, and Unit

Exceptions

• Scala | Exception Handling
• Throw Keyword in Scala
• Scala | Try-Catch Exceptions
• Scala | Finally Exceptions
• Scala | Either

Scala Annotation

• Scala | Annotation
• Scala | Self types Annotation

Methods

• Scala | Functions - Basics
• Currying Functions in Scala with Examples
• Anonymous Functions in Scala
• Higher Order Functions in Scala
• Scala | Named Arguments
• Scala | Functions Call-by-Name
• Scala | Closures
• Scala | Nested Functions
• Parameterless Method in Scala
• Recursion in Scala
• Tail Recursion in Scala
• Scala | Partially Applied functions
• Method Overloading in Scala
• Method Overriding in Scala
• Scala | Method Invocation
• Scala | Format and Formatted Method
• Controlling Method Scope In Scala
• Scala | Repeated Method Parameters
• Partial Functions in Scala
• Lambda Expression in Scala
• Scala Varargs
• Scala | Function Composition
• Call a method on a Super Class in Scala
• Implicit Conversions in Scala

String

• Scala String
• Scala | String Interpolation
• Scala | StringContext
• Regular Expressions in Scala
• StringBuilder in Scala
• String concatenation in Scala

Scala Packages

• Packages In Scala
• Scala | Package Objects
• Chained Package Clauses in Scala
• File Handling in Scala

Scala Trait

• Scala | Traits
• Scala | Sealed Trait
• Scala | Trait Mixins
• Trait Linearization in Scala
• Scala | Trait App
• Difference Between Traits and Abstract Classes in Scala
• Scala Trait Traversable

Collections

• Scala Lists
• Scala ListBuffer
• ListSet in Scala
• Scala | Arrays
• Multidimensional Arrays in Scala
• Scala | Create Array with Range
• Scala | ArrayBuffer
• Scala | Tuple
• Set in Scala
• BitSet in Scala
• HashSet In Scala
• Stack in Scala
• HashMap in Scala
• ListMap in Scala
• TreeSet in Scala
• Scala | Reduce, fold or scan
• Iterators in Scala
• Scala Map
• Scala | Methods to Call on a Map
• Scala | map() method

Scala Options

• Scala | Option
• Scala | Methods to Call Option
• Scala | unapplySeq() method

Miscellaneous Topics

• Getters and Setters in Scala
• Scala Extractors
• Scala For Comprehensions
• Scala | Sequence Comprehensions
• The Factory Pattern in Scala
• Scala | Lazy Evaluation
• Monads in Scala
• Lazy val and Infinite Sequences in Scala
• Scala Stream
• Recursive Streams and collection in Scala
• Placeholder Syntax in Scala
• Scala | Sieve of Eratosthenes
• Using Extractors with Pattern Matching In Scala
• Overriding Accessors and Mutators in Scala

Hello World in Scala

In Scala, writing a simple "Hello, World!" program is straightforward. Below are the steps to create and run such a program.

Using an IDE or Text Editor

1. Open your favorite IDE or text editor and create a new Scala file, usually with a .scala extension.
2. Write the following code in that file:

object HelloWorld {
  def main(args: Array[String]): Unit = {
    println("Hello, World!")
  }
}

1. Save the file as HelloWorld.scala.

2. Open a terminal and navigate to the directory where HelloWorld.scala is saved.

3. Compile the Scala file using scalac, the Scala compiler:

   scalac HelloWorld.scala
   

4. This will generate a HelloWorld.class file. You can run it using the scala command:

   scala HelloWorld
   

You should see "Hello, World!" printed to the terminal.

Using a Build Tool like sbt

1. Create a new sbt project directory and navigate to it.

2. Place the HelloWorld.scala file inside the src/main/scala/ directory of the sbt project.

3. Open a terminal and navigate to the sbt project directory.

4. Run the following command to execute your program:

   sbt run
   

sbt will compile and run your Scala program, and you should see "Hello, World!" printed to the terminal.

Using Scala REPL

1. Open Scala REPL (Read-Eval-Print Loop) by typing scala into the terminal.

2. You can directly print "Hello, World!" to the console as follows:

   println("Hello, World!")
   

These are some of the various ways you can write and run a "Hello, World!" program in Scala.