javascript - Efficient way to convert an array into an object where each key is a value of a member of the array -

suppose have data:

var obj = [  {    type: 1,    value: "abc"   },  {    type: 2,    value: "abcde"  },  {    type: 1,    value: "fghez"  } ]; 

is there efficient , elegant way in javascript transform object follows?

var sortedbytype = {   1: [ "abc", "fghez" ],   2: [ "abcde" ] } 

obviously can loop through every element in obj, read type property , add value new object, assembling result 1 one, below. kind of seems strange, long, inefficient , not elegant.

var sortedbytype = {}; (var = 0; < obj.length; i++) {   var type = obj[i].type;   if (!sortedbytype[type]) { sortedbytype[type] = []; }    sortedbytype[type].push(obj[i].value); } 

you use array#reduce object accumulator.

var array = [{ type: 1, value: "abc" }, { type: 2, value: "abcde" }, { type: 1, value: "fghez" }],      result = array.reduce(function (r, a) {          if (!r[a.type]) {             r[a.type] = [];          }          r[a.type].push(a.value);          return r;      }, object.create(null));    console.log(result);