define a class in javascript code example

Example 1: javascript class

class ClassMates{
	constructor(name,age){
    	this.name=name;
      	this.age=age;
    }
  	displayInfo(){
    	return this.name + "is " + this.age + " years old!";
    }
}

let classmate = new ClassMates("Mike Will",15);
classmate.displayInfo();  // result: Mike Will is 15 years old!

Example 2: javascript class

class Rectangle {
  constructor(height, width) {
    this.height = height;
    this.width = width;
  }
  // Getter
  get area() {
    return this.calcArea();
  }
  // Method
  calcArea() {
    return this.height * this.width;
  }
}

const square = new Rectangle(10, 10);

console.log(square.area); // 100

Example 3: javascript create class

class Car {
  constructor(brand) {
    this.carname = brand;
  }
}

Example 4: es6 class example

<script>
   class Student {
      constructor(rno,fname,lname){
         this.rno = rno
         this.fname = fname
         this.lname = lname
         console.log('inside constructor')
      }
      get fullName(){
         console.log('inside getter')
         return this.fname + " - "+this.lname
      }
   }
   let s1 = new Student(101,'Sachin','Tendulkar')
   console.log(s1)
   //getter is called
   console.log(s1.fullName)
</script>

Example 5: javascript class example

// to create a class named 'LoremIpsum':

class LoremIpsum {
  
  // a function that will be called on each instance of the class
  // the parameters are the ones passed in the instantiation

  constructor(a, b, c) {
    this.propertyA = a;
    
    // you can define default values that way
    this.propertyB = b || "a default value";
    this.propertyC = c || "another default value";
  }
  
  // a function that can influence the object properties
  
  someMethod (d) {
    this.propertyA = this.propertyB;
    this.propertyB = d;
  }
}






// you can then call it
var loremIpsum = new LoremIpsum ("dolor", null, "sed");

// at this point:
// loremIpsum = { propertyA: 'dolor',
//                propertyB: 'a default value',
//                propertyC: 'sed' }

loremIpsum.someMethod("amit");

// at this point:
// loremIpsum = { propertyA: 'a default value',
//                propertyB: 'amit',
//                propertyC: 'sed' }







.

Example 6: javascript classes

let Person = class {
  constructor(firstName, lastName) {
    this.firstName = firstName;
    this.lastName = lastName;
  }
}