Updated April 5, 2023
Difference Between Scala Class vs Object
The following article provides an outline for Scala Class vs Object. Class and object both are very different; they both are dependent on each other without one of them, we cannot do anything. To access the class methods, variables and other things, we required an object, and in order to create the object, we must have a class available for that. Classes are the blueprint for an object; it is also said to be an object constructor etc. If we are working with the object-oriented programming language, then classes and object are the basic concepts.
Head to Head Comparison Between Scala Class vs Object (Infographics)
Below are the top 9 differences between Scala Class vs Object:
Key Difference Between Scala Class vs Object
In the previous section, we have seen how we can define a class and object in scala; also, we have seen that classes and objects are the basic concepts of object-oriented programming language.
In this section, we will see the key points to see them better; see below for each of them:
- We know that classes are the user-defined logical entity that represents some entity from the real world. If we talk about an object, objects are the instance of the class. Inside the class, we have define or bind the data and their behavior into a single unit. Classes are also called or referred to as the prototype; by the use of it, we can create the object of the class. We can define member variable, fields, data, function inside the class and these turns represent a single unit in any programming language.
Define class and object in scala:
1. class: If we want to define a class in scala, then we have to use the ‘class’ keyword. This section will see how we can create a user-defined class in scala using the ‘class’ keyword.
Example:
class name_of_class
Here we are using the ‘class’ keyword to create a class in scala; immediately after the class keyword, we can give a user-defined name to our class.
Example:
class Demo{}
2. Object: Object is nothing but the class that is used to access the class functions or method, filed, etc.
Below see the steps to create the object in scala:
Example:
var object_name = new class_name;
In the above syntax, what we are doing is we are creating an object of the class, using the ‘new’ keyword in scala. This is the most common way to create an object in scala. The class name can immediately follow this.
Example:
var demoObj = new Demo();
- Here we are creating an object where we are mentioning the name of the class after the new keyword. Now, this reference will hold the Demo() class object, and all the member variable and methods can be accessed by using this object only.
This is the basic things which can be done to create a class or object in programming, but there are some specific things which are not mandatory but can be followed in scala:
1. Superclass: If we want to give any parent class while creating the class, we can do this in a scala. But for this, we will use the ‘extends’ keyword. This is normally referring to the parent-child relationship; this is not mandatory but can be done if required.
2. Class Name: It is always recommended to use an initial letter as capital while creating a class in scala. It is a standard or naming convention we can say everybody should follow.
3. Class Keyword: While creating a class ‘class’ keyword has to be used before the user-defined class name.
4. Body: After the class declaration, we can also define the body of the class as well. Where we can define our other stuff like constructor, methods and other fields.
5. Traits: This is also not mandatory, but this can be implemented while creating the class. We can use the ‘extends’ keyword, and we can implement several traits.
Object represent a real-world entity; the object has behavior, state and identity. An object is the instance of the class; without class, e cannot create an object; they are dependent on each other. To create the object, we also require a constructor as well.
Let’s discuss the property of the object:
- Identity: Identity represents the name of the object, and it should be unique. This identity enables us to interact with the other objects.
- Behavior: Behavior represents the interaction among the object.
- State: State of the object represent the attribute of the object, these attribute often represent the property of the object.
Scala Class vs Object Comparison Table
Let’s discuss the top comparison between Scala Class vs Object:
| Scala Class | Object |
| Classes are the blueprint; by the use of this, we can create the object. | Objects are the instance of the class; by the use of it, we can access class member variables, methods etc. |
| A class can be create by using the ‘class’ keyword. | An object can be created by using the ‘new’ keyword. |
| This is the basic unit for object-oriented programming language. | Objects are also the basic unit for object-oriented programming language. |
| If we want to create a class, then we have to declare it only once. | We can create the object for the same class, again and again, any number of time we want. |
| Classes does not take or consume any space in the stack or memory of the program; they are just the logical entities for the program. | But when we create an object, they occupy some space in memory, so we should be careful while creating multiple instances for the same class; it may lead to some performance issue. |
| Classes represent the logical existence. | While on the other side object represents physical existence. |
| Classes are said to be the group of the objects. | To access this member variable, methods and other stuff of the class, we may require an instance, so the object provides us with a way to access class behaviors and functions. |
| Classes can be declare or created in only one way possible. | While on the other side object represents the real-world entity such as Animal, Pen, Spoon etc. |
| Example: class name_of_class.
In the above lines of code, we can create a class using the class keyword followed by the ‘name’ of the class in scala. |
Objects can be cared for by using multiple ways available in Scala.
Example: new class_name. In the above lines of code, we can create an object of the class by using the ‘new’ keyword in scala followed by the name of the class. |
Conclusion
In this way, we know that classes and objects are interrelated also cannot be used without each other. Classes are the prototype, and objects are the real-world entity in an object-oriented programming language.
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This is a guide to Scala Class vs Object. Here we discuss the Scala Class vs Object key differences with infographics and comparison table. You may also have a look at the following articles to learn more –
