React Js Check if Key Exist in object

<!DOCTYPE html>
<html>

useEffect(() => {
                setKeyExists(keyToCheck in myObject);
                setKeyValue(keyExists ? myObject[keyToCheck] : null);
            }, [keyToCheck, myObject, keyExists]);

return (
                <div className='container'>
                    <h3>React Js Check if key is exist in object</h3>
                    {keyExists ? (
                        <p>Key <strong>{keyToCheck}</strong> exists in the object. Value: <strong>{keyValue}</strong></p>
                    ) : (
                        <p>Key <strong>{keyToCheck}</strong> does not exist in the object.</p>
                    )}
                </div>
            );
        }

ReactDOM.render(<App />, document.getElementById("app"));
    </script>

.container {
            margin: 0 auto;
            width: 600px;
            text-align: center;
            box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.12), 0 2px 4px 0 rgba(0, 0, 0, 0.24);
            padding: 20px;
        }

h3 {
            color: #333;
            font-size: 18px;
            margin-bottom: 10px;
        }

p {
            color: #666;
            font-size: 16px;
        }

strong {
            color: #000;
        }
    </style>
</body>

</html>