sample.js

var people = [{
        name: 'anne',
        pets: ['dog', 'cat']
    },
    {
        name: 'jim',
        pets: ['dog']
    },
    {
        name: 'sam',
        pets: ['rabbit', 'cat']
    },
    {
        name: 'kay',
        pets: ['dog', 'hamster']
    },
    {
        name: 'olive',
        pets: ['fish', 'cat']
    }
];
for (let i = 0; i < people.length; i++) {
    console.log(people[i].name);
    for (let j = 0; j < people[i].pets.length; j++) {
        console.log(people[i].pets[j]);
    }
}