Modular Programming with JavaScript

Re-factoring to a more modularized approach

Let's consider re-factoring the two functions that we looked at previously and putting them together in a more specialized package (class or module) called, CalculationHandler, as shown below:

function CalculationHandler(){
  CalculationHandler.result = null;
}

CalculationHandler.doAddition = function(num1, num2){
  return num1 + num2;
};

CalculationHandler.doSubtraction = function(num1, num2){

  if(num1 > num2){
    CalculationHandler.result = num1 - num2;

  }else{
    CalculationHandler.result = num2 - num1; 
  }
  return CalculationHandler.result;

};

console.log(CalculationHandler.doAddition(3,2)); // displays 5
console.log(CalculationHandler.doSubtraction(3,2)); // displays 1

As you can see in this "module" (and I use ...