I have a array of objects for use in D3 e.g
var cities = [
{ city: "London", country: "United Kingdom", index: 280 },
{ city: "Geneva", country: "Switzerland", index: 259 },
{ city: "New York City", country: "United States", index: 237 },
{ city: "Singapore", country: "Singapore", index: 228 },
{ city: "Paris", country: "France", index: 219 },
{ city: "San Francisco", country: "United States", index: 218 },
{ city: "Copenhagen", country: "Denmark", index: 217 },
{ city: "Sydney", country: "Australia", index: 215 },
{ city: "Hong Kong", country: "Hong Kong", index: 214 },
{ city: "Brisbane", country: "Australia", index: 208 }
}
I would like to order the objects in ascending order based on their cities.index property. So that I can display them as such in D3.js
. Im sure there is a way of doing this in D3 but I am yet to figure it out when dealing with an array of objects.
Any help?
You can pass an anonymous function to the Javascript Array.prototype.sort
to sort by index
. D3 has a function d3.ascending
(v 3.x) that makes it easy to sort ascending:
cities.sort(function(x, y){
return d3.ascending(x.index, y.index);
})
And here's the output:
[
{"city":"Brisbane","country":"Australia","index":208},
{"city":"Hong Kong","country":"Hong Kong","index":214},
{"city":"Sydney","country":"Australia","index":215},
{"city":"Copenhagen","country":"Denmark","index":217},
{"city":"San Francisco","country":"United States","index":218},
{"city":"Paris","country":"France","index":219},
{"city":"Singapore","country":"Singapore","index":228},
{"city":"New York City","country":"United States","index":237},
{"city":"Geneva","country":"Switzerland","index":259},
{"city":"London","country":"United Kingdom","index":280}
]