function isEqual(firstObj, secondObj) {
  const firstKeys = Object.keys(firstObj);
  const secondKeys = Object.keys(secondObj);

  if (firstKeys.length !== secondKeys.length) {
    return false;
  }

  return firstKeys.every(function (key) {
    return firstObj[key] === secondObj[key];
  });
}

const first = {
  property: 'value',
  anotherProperty: 'another value'
};

const second = {
  property: 'value',
  anotherProperty: 'another value'
};

const third = {
  property: 'value',
  anotherProperty: 'one more value'
};

isEqual(first, second); // true
isEqual(second, third); // false