JavaScript Filters

I’ve you’ve ever had to store some data for a simple, mostly-static website, the JavaScript filter function is extremely helpful.

Imagine an array of movie franchise objects like this:

var movieFranchises = [
    {
        id: 1,
        name: "Star Wars",
        rank: 1,
        boxOffice: 4.2
    },
    {
        id: 2,
        name: "Harry Potter",
        rank: 6,
        boxOffice: 4.2
    },
    {
        id: 3,
        name: "Lord of the Rings",
        rank: 2,
        boxOffice: 1.86
    }
];

What if you wanted to find the franchises with a rank in the Top 5 that also made more than $2 billion dollars?

Using filters, you could do something like this:

function filterMovies(m) {
    return m.rank <= 5 && m.boxOffice >= 2;
}
var goodMovies = movieFranchises.filter(filterMovies);

console.log(goodMovies);

Voila! The goodMovies variable now stores an array of all the movies that meet the criteria.