feat(JS): add a comment

Author: josueJURE

index.js

@@ -3,14 +3,11 @@ const historyElement = document.querySelector(".computation-history");
 let screen = document.querySelector("[data-screen]");
 const historyBtn = document.querySelector(".history-btn");
 const slidingPart = document.querySelector(".sliding-part");
-const computationHistoryParent = document.querySelector(
-  ".computation-history-parent"
-);
+const computationHistoryParent = document.querySelector(".computation-history-parent");
 const operators = document.querySelectorAll("[data-operator]");
 const clearHistoryBtn = document.querySelector(".clear-history-btn");
 
-clearHistoryBtn.addEventListener("click", () => {
-  historyElement.innerHTML = "";
+clearHistoryBtn.addEventListener("click", () => {historyElement.innerHTML = "";
 });
 
 const operatorRegex = /[\/*\-+]/;
@@ -194,7 +191,7 @@ function userClicksOnEqualButton(button) {
         screen.innerText = "0÷0 is an invalid format. Press AC";
       } else {
         let result = eval(replacedArray.join(""));
-        let historyEntries = [[...replacedArray, "=", result]];
+        let historyEntries = [[...replacedArray, "=", result]]; // Used slice() at firest. But slice() is not sufficient because it only creates a shallow copy of the array, and modifications to the new array will still affect the original array. The spread syntax ([...replacedArray]), which creates a shallow copy as well, is a concise way to create a new array with the same elements as the existing array. While ensuring that modifications to historyEntries do not affect replacedArray, and vice versa.
         replacedArray.splice(replacedArray.length, 0, "=", result);
         displayResult(replacedArray, result);
         screen.innerText = !Number.isFinite(result)