round real subtraction result to after comma len

src/Subtraction.js

@@ -1,7 +1,7 @@
 import React, {useState, useEffect, useRef} from "react";
 import DataGrid, {Column} from "devextreme-react/data-grid";
 import {Alert} from "./AlertDialog.js";
-import {addNumbersToGrid, numbersToArrOfArr} from "./helpers.js";
+import {addNumbersToGrid, numbersToArrOfArr, afterCommaLen} from "./helpers.js";
 import "./App.css";
 
 let imdtRes;
@@ -12,7 +12,7 @@ let noOfDigits = 0;
 function Subtraction() {
   const [input, setInput] = useState(""); // initial user input like 34+56.7
   const [realResult, setRealResult] = useState(0); // real result of calculation
-  const [carryArr, setCarryArr] = useState([]); // array of carries [1","0"]
+  const [carryArr, setCarryArr] = useState([]); // array of carries ["1","0"]
   const [commaIdx, setCommaIdx] = useState(0); // int: comma position
   const [numbers, setNumbers] = useState(0); // array of arrays with input numbers
   const [showAlert, setShowAlert] = useState(false);
@@ -72,6 +72,9 @@ function Subtraction() {
       for (let i=1; i<numbers.length; i++){
         realRes -= numbers[i]
       }
+
+      let afterComma = Math.max(...numbers.map(x => afterCommaLen(x)));
+      realRes = parseFloat(realRes.toFixed(afterComma));
       setRealResult(realRes);
 
       let [numbersArr, commaIdx] = numbersToArrOfArr(numbers);

src/helpers.js

@@ -11,7 +11,7 @@
 }
 
 
-const afterCommaLen = (number) => {
+export const afterCommaLen = (number) => {
   let noStrList = number.toString().split(".");
   if (noStrList.length > 1){
     return noStrList[1].length