constructor function javascript es6 code example

Example 1: javascript class constructor

class Person {
  constructor(name, age) {
    this.name = name;
    this.age = age;
  }
}

const person = new Person("John Doe", 23);

console.log(person.name); // expected output: "John Doe"

Example 2: javascript classes

//use classes by initiating one like so:
class MyClass {
	constructor(FirstProperty, SecondProperty, etcetera) {
    	//The constructor function is called with the new class 
      	//instance's parameters, so this will be called like so:
      	//var classExample = new MyClass("FirstProperty's Value", ...)
      this.firstProperty = FirstProperty;
      this.secondProperty = SecondProperty;
    }
  //creat methods just like functions:
  method(Parameters) {
  	//Code Here
  }
  //getters are properties that are calculated when called, versus fixed
  //variables, but still have no parenthesis when used
  get getBothValues() 
  {
  	return [firstProperty, secondProperty];
  }
}
//Note: this is all syntax sugar reducing the boilerplate versus a
// function-defined object.

Example 3: 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 4: how to create instance of class in javascript

class Hello {
	person(name){
    	this.name = name;
    }
  	// Constructor - Important except for JSX
    constructor(name){
    	this.person(name);
        console.log(`Hello ${this.name}`);
    }
}

const helloInstance = new Hello('john doe');

Example 5: class declaration in javascript

class NameOfClass {
//class declaration first letter should be capital it's a convention
  obj="text";
  obj2="some other text";
}
//always call class with "new" key word
console.log(new NameOfClass);