Factory functions

Factory function introduction

The factory function pattern is similar to constructors, but instead of using new to create an object, factory functions simply set up and return the new object when you call the function. Check out this example:

function createTaxCalculator(tax) {
    function calculateTax(amount) {
        return amount * tax;
    }
    return calculateTax;
}

const calculateVatAmount = createTaxCalculator(0.19);
const calculateIncomeTaxAmount = createTaxCalculator(0.25);

console.log(calculateVatAmount(100));
console.log(calculateVatAmount(200));