Question

I have an array like this:

  var movies = [
  { Name: "The Red Violin", ReleaseYear: "1998", Director: "François Girard" },
  { Name: "Eyes Wide Shut", ReleaseYear: "1999", Director: "Stanley Kubrick" },
  { Name: "The Inheritance", ReleaseYear: "1976", Director: "Mauro Bolognini" }
  ];

I want to find the location of the movie that’s released in 1999.

Should return 1.

What’s the easiest way?

Thanks.

Answer 1

You will have to iterate through each value and check.

for(var i = 0; i < movies.length; i++) {
    if (movies[i].ReleaseYear === "1999") {
        // i is the index
    }
}

Since JavaScript has recently added support for most common collection operations and this is clearly a filter operation on a collection, instead you could also do:

var moviesReleasedIn1999 = movies.filter(function(movie) {
    return movie.ReleaseYear == "1999";
});

assuming you’re not interested in the indexes but the actual data objects. Most people aren’t anyways 🙂

.filter is not supported in all browsers, but you can add it yourself to your code base:
https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Array/filter#Compatibility