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So this is the introduction of object oriented programming in JavaScript.

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It was known as OOP.

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OOP stands for Object Oriented Programming and it was introduced in ES6 version of JavaScript.

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Object oriented programming is a coding methodology or a style or a pattern.

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It is introduced to convert our big line of code into a smaller line of code.

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With this, we can make our code more modular and reusable that we can use that code over and over again.

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It makes our code well organized, and let's make our code very easier to debug.

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Debug.

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I mean, if there is an error in our code and the method, the catching the error is called debug.

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Basically, we do not use object oriented programming for small task.

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It is used for big and complex projects.

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It is currently used in various JavaScript framework like React.js, AngularJS, Vue.js and these are

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all based on modern JavaScript.

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If you want to understand object oriented programming, first you need to understand two terms.

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First one is class and second one is object.

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If you understand these two concepts, then you understand 50% of object oriented programming and the

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OOP concept used in every high level programming language.

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So at first let's try to understand what is class and objects.

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Let's try to explain it with graphical images.

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Suppose we have a blueprint of a building and a builder build houses with this blueprint.

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So according to the blueprint, every building the builder make is similar.

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All building designs are identical.

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As you can see, the blueprint has three bedrooms and one kitchen, so every building is pretty similar.

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So we can accept our blueprint as a class.

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And all the buildings made by this blueprint are objects.

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The point is, objects are made with this class.

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Let me show you another example and it little advance.

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Suppose we have a class named car and these are two actual cars.

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First one is Maruti Swift and second one is Toyota Fortuner.

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So we create a class named car.

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And our actual cars are objects which is made by the car class.

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And as you know, every car have some common properties like their color engine seat, their AC and

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their prices.

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We call them properties in programming language and these properties are associated with one or more

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classes.

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Every class have their own property.

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As you can see, we have two actual cars, Swift and Fortuner.

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Their properties are same, but their value is different.

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As you can see Maruti have four color option but Toyota have five color option.

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Maruti provide 1200 cc engine and Toyota provide 2700 cc engine.

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Maruti provide five seat and Toyota provide seven seat and both the car provide SC and also you can

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see there is huge price difference between these two.

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Car properties are basically a variable and we can set different value for this variable.

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And if you want to change and manipulate the values, then you need to use methods.

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Our classes are made with properties and methods.

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Suppose I create a class named calculation.

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Then I create some variable as properties.

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We declare these three variable within this class, and if you want to assign values to these properties,

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you need methods.

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Methods are basically functions.

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Suppose we want to add numbers.

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So I'm going to create a function named sum.

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And as you can see we perform some calculation in this function.

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First we take a variable name c and then add two variables a and b and we return c.

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We can use only those property in our method, which we already declared in our class, and we cannot

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use properties which is defined in outside the classes.

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Here you can see we just create one method in our class, but you can create multiple methods in this

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class at the same way.

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I'm going to create another method name sub sub mean subtraction.

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So let me show you the syntax how we can declare class.

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And also I'm going to show you how we can create property and methods.

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Suppose I'm going to create a class name.

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Hello.

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So at first we need to type class keyword.

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Then our class name which is hello.

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Then inside the curly braces.

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Here we need to create properties and method inside this class.

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Suppose I want to create a method named methods for that.

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First we need to take the method name in our case masses.

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It's a normal function just here we don't need.

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To use function keyword before the function name.

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At the same way, for parameters, we need to use parenthesis.

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Then inside the curly braces we can define our masses.

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In our case I want to print.

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Hello everyone in our console.

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Now masses become a method.

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You can create multiple methods in a class and if you want to call this method first you need to create

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an object using this class.

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So first we need to take a variable in our case A and assign this class.

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Also to assign this class we need to use new keyword.

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Then our class name.

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This will turn our variable into an object.

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After creating this object, we can access all the properties and methods from this class.

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Suppose I want to call masses method.

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Then first we need to type the object name in our case a dot.

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Our method name message.

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And if you want to send any argument then you can do.

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Usually we need to do it for function.

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So this is it for this tutorial.

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In the next tutorial we are going to learn about practical.

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So thanks for watching this video.

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Stay tuned for the next tutorial.