javascript - transform JSON array of objects, create new property from two property values -

i have json data looks this, each object has 3 properties:

data = [       {            "country" : "ireland",            "year" : "2013",           "number" : 45       },       {            "country" : "ireland",            "year" : "2014",           "number" : 23430        },       {            "country" : "honduras",            "year" : "2013",           "number" : 1582       },       {            "country" : "honduras",            "year" : "2014",           "number" : 3458       }     ] 

i want transform data there 2 properties per object. property named "country" remain same. want combine other 2 properties, value of "year" becomes key of new property, , value of "number" value of new property. new json array of objects this:

    newdata = [       {            "country" : "ireland",            "2013" : 45,            "2014" : 23430       },       {            "country" : "honduras",            "2013" : 1582,            "2014" : 3458       }     ] 

how go doing that? i've done lot of searching , can't find solution. i'd prefer use javascript , not library.

just go through each of data items , add items result array. can create map keep track of countries you've seen through iteration quick access.

var newdata = [],     countries = {}; data.foreach(function (d) {     var country = countries[d.country];     if (!country) {         newdata.push(country = countries[d.country] = {});     }     country[d.year] = d.number; });