uh yeah! I trust you are doing great? Today, I will be explaining everything you need to know that would help foster your understanding of classes, inheritance, and constructors in software development.
Understanding the concept behind these terms might seems to be difficult when you are just learning how to code or you probably trying to level up and improve more on your existing skillset.
What is a Constructor?
A constructor is a special method in C# and other programming languages that is automatically invoked at the time of object creation. Generally, it is used to configure the new object data members. The constructor in C# has the same name as the structure or class.
In simpler terms, think of it as something that runs first when an object of a class is created. I will be explaining what classes are and how a constructor can be created in a class shortly.
In C# we have two types of constructors, which are
- Constructor with parameters
- Default constructor
The term constructor can be used in every other programming languages but I will show you examples in two different programming languages(C# and JavaScript)
Constructor with parameters
Constructors with parameters are constructors that have parameters and can be used to provide distinct objects with various values.
Example of a constructor with parameters with CSharp
using System;
public class Student
{
public int id;
public String name;
public float income;
public Student(int studentId, String studentName, float studentIncome)
{
id = studentId;
name = studentName;
income = studentIncome;
}
public void display()
{
Console.WriteLine(id + " ," + name + " ," + income);
}
}
class StudentTest{
public static void Main(string[] args)
{
Student studentA = new Student(001, "Ade", 590000);
Student studentB = new Student(012, "Alesh", 909000);
studentA.display();
studentA.display();
}
}
Example of a constructor with parameters with JavaScript
class Student {
constructor(studentId, studentName, studentIncome) {
this.studentId = studentId;
this.studentName = studentName;
this.studentIncome = studentIncome;
}
display() {
console.log(
`Hello, my name is ${this.studentName} with id ${this.studentId} and income: ${this.studentIncome}`
);
}
}
const selectStudentA = new Student(1, 'Ade', 490000);
const selectStudentB = new Student(2, 'Alesh', 590000);
selectStudentA.display();
selectStudentB.display();
Default constructor
As a default constructor, a constructor that has no argument is defined. It is invoked at the moment of object formation.
Example of Default constructor with CSharp
using System;
public class Student
{
public Student()
{
Console.WriteLine("Constructor invoked successfully");
}
}
public static void Main(string[] args)
{
Student studentA = new Student();
Student studentB = new Student();
}
Example of Default constructor with JavaScript
class Student {
Student() {
console.log('Constructor invoked successfully');
}
}
const selectStudentA = new Student();
const selectStudentB = new Student();
What is Inheritance?
Inheritance is a mechanism in which all the properties and behaviors of its parent object are inherited automatically by one object.
In this way, it is possible to reuse, expand or change the attributes and behaviors which are described in another class.
Inheritance Concepts
- Base Class (parent) - from which the class is inherited
- Class derived (child) - the class inherited from another class
Example of Inheritance with CSharp
using System;
public class Student
{
public float income = 90000;
}
public class Best: Student
{
public float bonus = 10000;
}
class BestStudent{
public static void Main(string[] args)
{
Best student = new Best();
Console.WriteLine("Income: " + student.income);
Console.WriteLine("Bonus: " + student.bonus);
}
}
Example of Inheritance with JavaScript
class Student {
constructor() {
this.income = 90000;
}
}
class Best extends Student {
constructor() {
super();
this.bonus = 10000;
}
}
const bestStudent = new Best();
console.log(`Income: ${bestStudent.income}`);
console.log(`Bonus: ${bestStudent.bonus}`);
What is a Class?
I'm pretty sure by now you can guess what a class can be referred to.
A class is like a particular object blueprint. Every object has some color, form, and functionality in the real world - the Range Rover luxury car, for example.
The Range Rover is a luxury car-type object. The luxury car is a class that displays certain features, such as speed, color, form, interior, etc.
Example of a class
class Student
{
public float income = 90000;
}
Conclusion
I hope you now completely understand inheritance, constructor, and I hope the C# and Javascript examples ease the learning process.
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See you in my next blog article. Take care!!!
