Neighborhoods - Associative Arrays

function solve(input) {
    let map = new Map();
    let neighborhoods = input.shift().split(', ');

    for(let neighborhood of neighborhoods) {
        map.set(neighborhood, []);
    }

    for(let i = 0; i < input.length; i++) {
        let current = input.shift().split(' - ');
        let neighborhood = current[0];
        let person = current[1];
        if(neighborhoods.includes(neighborhood)) {
            map.get(neighborhood).push(person);
        }
    }

    let sorted = Array.from(map).sort((a, b) => {b[0] - a[0]});
    let neighborhoodName = sorted[0];
    let persons = sorted[1];
    for(let neighborhoodName of sorted) {
        console.log(`${neighborhoodName}: ${persons.length}`);
        for(let j = 0; j < persons.length; j++) {
            console.log(`--${persons[j]}`);
        }
    }
}

solve(['Abbey Street, Herald Street, Bright Mews',
    'Bright Mews - Garry',
    'Bright Mews - Andrea',
    'Invalid Street - Tommy',
    'Abbey Street - Billy'])