filter examples

by jcreamer898

HTML

<pre id="results"></pre>

JavaScript

var movies = [{ name: 'star wars', year: 1977}, { name: 'the matrix', year: 1999 }, { name: 'the fellowship of the ring', year: 2001 }];

var names = movies.reduce(function(memo, m) {
    if (m.year > 2000) {
        memo.push(m.name);
    }
    
    return memo;
}, []);

var result = document.createElement('div');
result.innerHTML = JSON.stringify(names, null, 4);
document.getElementById("results").insertBefore(result);

var itemPrices = [9.99, 19.99, 99999.99, 29.99, 99.99];

var total = itemPrices.reduce(function(memo, p) {
    return memo + p;
}, 0).toFixed(2);

var result = document.createElement('div');
result.innerHTML = total;
document.getElementById("results").insertBefore(result);

var moviesByYear = movies.reduce(function(memo, m) {
    (memo[m.year] || (memo[m.year] = [])).push(m);
    return memo;
}, {});

var result = document.createElement('div');
result.innerHTML = JSON.stringify(moviesByYear, null, 4);
document.getElementById("results").insertBefore(result);