let user = {
  name: "John Doe",
  age: 40
};
// 'key' in object;
// object.hasOwnProperty('key');
// object?.key


































// const checkIfKeyExist = (objectName, keyName) => {
//     let keyExist = Object.keys(objectName).some(key => key === keyName);
//     return keyExist;
// };