Working in POJOs

function countScores(people){
    let peopleObject = {};

    for (let person of people) {
        let { name, score } = person;

        // If the name is not in the peopleObject, initialize it with the score.
        // Otherwise, add the score to the existing value.
        if (!(name in peopleObject)) {
            peopleObject[name] = score;
        } else {
            peopleObject[name] += score;
        }
    }

    return peopleObject
}

// Example 1:
const ppl = [
  { name: "Anthony", score: 10 },
  { name: "Fred", score : 10 },
  { name: "Anthony", score: -8 },
  { name: "Winnie", score: 12 }
];

console.log(countScores(ppl))