Reduce array of objects into object [duplicate]

Answer 1

Using Array#forEach.

var data = [ { name: 'foo', type: 'fizz', val: 9 }, { name: 'boo', type: 'buzz', val: 3 }, { name: 'bar', type: 'fizz', val: 4 }, { name: 'car', type: 'buzz', val: 7 }, ], 
    res = {};
    data.forEach(v => res[v.val] = v.name);

    console.log(res);

Using Array#reduce.

var data = [ { name: 'foo', type: 'fizz', val: 9 }, { name: 'boo', type: 'buzz', val: 3 }, { name: 'bar', type: 'fizz', val: 4 }, { name: 'car', type: 'buzz', val: 7 }, ],
    res = data.reduce(function(s,a){
      s[a.val] = a.name;
      return s;
    }, {});
  
    console.log(res);