1const person1 = {};
2person1['firstname'] = 'Mario';
3person1['lastname'] = 'Rossi';
4
5console.log(person1.firstname);
6// expected output: "Mario"
7
8const person2 = {
9 firstname: 'John',
10 lastname: 'Doe'
11};
12
13console.log(person2['lastname']);
14// expected output: "Doe"