js array functions

js array func

// filter active items
const filtered = items.filter(item => item.isActive == 10);

// map name and title 
const mapped = items.map(item => `${item.name} ${item.title}`);

// sort the item by year, oldest to yongest
const sorted = items.sort((a, b) => a.year > b.year ? 1 : -1);

// calculate total
const totalAmount = items.reduce((total, item) => {
    return total += (item.price + 10); 
}, 0);

// sort by years lived
const oldest = items.sort((a, b) {
    const lastGuy = a.passed - a.year;
    const nextGuy = b.passed - b.year;
    return lastGuy > nextGuy ? -1 : 1;
});

// get all words by de from webpage
const category = document.querySelector('.mw-category');
const links = Array.from(category.querySelectorAll('a'));
const de = links
                .map(link => link.textContent)
                .filter(streetName => streetName.includes('de'));

// sort on lastname 
const people = ['Riju, Das', 'Dhruba Das'];
const sorted = people.sort((lastOne, nextOne) => {
    const [aLast, aFirst] = lastOne.split(', ');
    const [bLast, bFirst] = nextOne.split(', ');
    return aLast > bLast ? 1 : -1;
});
console.table(sorted);

// count instances
const products = ['car', 'bike', 'car', 'car', 'bike', 'truck', 'truck', 'van'];
const total = products.reduce((obu, item) {
    if (!obj[item]) {
        obj[item] = 0;
    }
    obj[item]++;
    return obj;
}, {});