Learn the syntax, data types, and operations essential for programming in Scala

Become a Scala Developer

In this module, we will learn Scala from the ground up. This module aims to teach us how to write basic programs, assuming we have no prior knowledge of the language. We will start with a brief introduction to Scala to understand its functionality and applications. We will then move discuss the key features and functions of the language (data types, functions, classes, etc.) in detail. In the end, we will have all the basic knowledge of how to program in Scala.

Learn Scala from Scratch

A bluprint is used to create identical copies of the same object.

A bluprint is used to create identical copies of the same object.

The members of a class can be divided into the following two parts:

The members of a class can be divided into the following two parts:

An instance a singular occurence of something the same way an object is a single occurence of a class.

Why is an object known as an *instance* of a class?

Why is an object known as an instance of a class?

Members of the class are incorrectly defined

The code below declares a `EqualShape` class and creates its instance `sqaure`.
Why will the code not compile?

```
class EqualShape{
  var numOfSides: Int = 0
  var lengthOfSides: Int = 0

  def perimeter = numOfSides * lengthOfSides
}

val square = EqualShape 
```

The code below declares a <code>EqualShape</code> class and creates its instance <code>sqaure</code>.
Why will the code not compile?
<pre><code>class EqualShape{
 var numOfSides: Int = 0
 var lengthOfSides: Int = 0

 def perimeter = numOfSides * lengthOfSides
}

val square = EqualShape 
</code></pre>

What will be the output of the following code?

```
class EqualShape{
  var numOfSides: Int = 0
  var lengthOfSides: Int = 0

  def perimeter = numOfSides * lengthOfSides
}

val square = new EqualShape
val triangle = new EqualShape 
square.numOfSides = 4
square.lengthOfSides = 5

print(triangle.perimeter)
```

What will be the output of the following code?
<pre><code>class EqualShape{
 var numOfSides: Int = 0
 var lengthOfSides: Int = 0

 def perimeter = numOfSides * lengthOfSides
}

val square = new EqualShape
val triangle = new EqualShape 
square.numOfSides = 4
square.lengthOfSides = 5

print(triangle.perimeter)
</code></pre>

When we can pass arguments to an object class, this means that the class was defined using....

When we can pass arguments to an object class, this means that the class was defined using…

Point x location : 5
Point y location : 10

Point x location : 6
Point y location : 12

Point x location : 11
Point y location : 22

Point x location : 1
Point y location : 2

What will be the output of the follwoing code?

```
class Point(xc: Int, yc: Int) {
  var x: Int = xc
  var y: Int = yc

  def move(dx: Int, dy: Int) {
    x = x + dx
    y = y + dy
    println ("Point x location : " + x);
    println ("Point y location : " + y);
   }
}

val point = new Point(5, 10)

point.move(point.x+1, point.y+2)
```

What will be the output of the follwoing code?
<pre><code>class Point(xc: Int, yc: Int) {
 var x: Int = xc
 var y: Int = yc

 def move(dx: Int, dy: Int) {
 x = x + dx
 y = y + dy
 println (&quot;Point x location : &quot; + x);
 println (&quot;Point y location : &quot; + y);
 }
}

val point = new Point(5, 10)

point.move(point.x+1, point.y+2)
</code></pre>

A singleton object is created using the `object` keyword while a class is created using the `class` keyword.

A singleton object only has a single instance, unlike a class which has multiple instances.

A singleton object cannot be created using the `new` keyword while a class object must be created using the `new` keyword.

What is the difference bewteen a singleton object and a class?

What is the difference bewteen a singleton object and a class?

A companion object can access private members of its companion class.

A companion object can access private members of its companion class.

They are used as an entry point of a Scala application.

They can be used anywhere in the program, hence, allow easy access.

What is the use of stand alone objects?

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And with this last quiz, our course comes to an end. Before we part ways, let's look at where we should go from here.

In the following quiz, you will be tested on concepts you learned in this chapter.

Getting to Know Scala

Variables and Types

Operating with Operators

Strings and How to Use Them

Scala's Collection Library

Control Structures

Getting Started with Functions

Higher-Order Functions

Classes and Objects

Conclusion

Chapter Quiz