Prepare app

src/App.css

@@ -3,7 +3,7 @@
 }
 
 .App-logo {
-  height: 40vmin;
+  height: 10vmin;
   pointer-events: none;
 }
 
@@ -24,10 +24,6 @@
   color: white;
 }
 
-.App-link {
-  color: #61dafb;
-}
-
 @keyframes App-logo-spin {
   from {
     transform: rotate(0deg);

src/App.js

-import React from 'react';
-import logo from './logo.svg';
-import './App.css';
+import React, { useEffect, useCallback, useState, useMemo } from "react";
+import logo from "./logo.svg";
+import "./App.css";
+
+const Inputs = { toDecimal: "toDecimal", toRoman: "toRoman" };
 
 function App() {
+  // form
+  const [toDecimalValue, setToDecimalValue] = useState("");
+  const [toRomanValue, setToRomanValue] = useState("");
+
+  const handleChange = useCallback(e => {
+    e.preventDefault();
+    const value = e.target.value.trim().toUpperCase();
+    if (value) {
+      if (e.target.name === Inputs.toDecimal) {
+        setToDecimalValue(value);
+      } else {
+        setToRomanValue(value);
+      }
+    }
+  }, []);
+
+  useEffect(() => {
+    console.log(toDecimalValue, toRomanValue);
+  }, [toDecimalValue, toRomanValue]);
+
+  // convert values
+  const converted = useMemo(() => {
+    const romanToBeConverted = toDecimalValue;
+    const decimalToBeConverted = toRomanValue;
+    return {
+      toDecimal: 499,
+      toRoman: 'CDXCIX'
+    };
+  }, [toDecimalValue, toRomanValue]);
+
   return (
     <div className="App">
       <header className="App-header">
         <img src={logo} className="App-logo" alt="logo" />
-        <p>
-          Edit <code>src/App.js</code> and save to reload.
-        </p>
-        <a
-          className="App-link"
-          href="https://reactjs.org"
-          target="_blank"
-          rel="noopener noreferrer"
-        >
-          Learn React
-        </a>
+
+        <h2>Converter: Roman to Decimal</h2>
+        <input name={Inputs.toDecimal} onChange={handleChange} />
+        <span>Value is: {converted.toDecimal}</span>
+
+        <h2>Converter: Decimal to Roman</h2>
+        <input name={Inputs.toRoman} onChange={handleChange} />
+        <span>Value is: {converted.toRoman}</span>
       </header>
     </div>
   );