Strategy Pattern

function Flipkart() {
  this.getPrice = function (productName) {
    return `Flipkart:: Price for item ${productName}: is $10`;
  };
}

function Amazon() {
  this.getPrice = function (productName) {
    return `Amazon:: Price for item ${productName}: is $11`;
  };
}

function Price() {
  this.setWebsiteName = function (websiteName) {
    this.websiteName = websiteName;
  };

  this.getPrice = function (productName) {
    return this.websiteName.getPrice(productName);
  };
}

const priceFromFlipkart = new Price();
priceFromFlipkart.setWebsiteName(new Flipkart());

console.log(priceFromFlipkart.getPrice("S24"));

const priceFromAmazon = new Price();
priceFromAmazon.setWebsiteName(new Amazon());

console.log(priceFromAmazon.getPrice("S24"));

class Flipkart {
  constructor() {}
  getPrice(productName) {
    return `Flipkart:: Price for item ${productName}: is $10`;
  }
}

class Amazon {
  constructor() {}
  getPrice(productName) {
    return `Amazon:: Price for item ${productName}: is $11`;
  }
}

class Price {
  constructor(websiteName) {
    this.websiteName = websiteName;
  }
  getPrice(productName) {
    return this.websiteName.getPrice(productName);
  }
}

const priceFromFlipkart = new Price(new Flipkart());

console.log(priceFromFlipkart.getPrice("S24"));

const priceFromAmazon = new Price(new Amazon());

console.log(priceFromAmazon.getPrice("S24"));