13. JavaScript Programming Paradigms

Activity 13.01: Creating a Calculator App

Solution

1. Create an empty file and call it procedural.js.
2. Initialize an array that will maintain the history of function calls:

   lethistoryList = [];

3. Now, create simple addition, subtraction, multiplication, division, and power functions:

   procedural.js

   3 function add(a, b){
   4 historyList.push(['ADD', a, b]);
   5 return a+b;
   6 }
   7 
   8 function subtract(a, b){
   9 historyList.push(['SUB', a, b]);
   10 return a-b;
   11 }
   12 
   13 function multiply(a,b){
   14 historyList.push(['MUL', a, b]);
   15 return a*b;
   16 }

   The full code is available at: https://packt.live/2Xf6kHk

4. Create a history function, which will maintain the history of function calls:

   function history(){
    historyList.map((command, index)=>{
     console.log(index+1+'.', command.join(' '));
    })
   }Call all...