展平多个嵌套的层次结构数组 - d3.js

Question

I have an an array with four levels that I would like to have flattened.

Simplified code with two starting array-elements and flattening of the lowest level:

var tstArray = [{Count:2,Yr:2008,Dep:"NDep_1",Periodtype:"Week",Period:1,Beds:5},
                {Count:9,Yr:2008,Dep:"NDep_2",Periodtype:"Week",Period:1,Beds:10}
                ];
console.log(tstArray);

tstArray = d3.nest()
                    .key(function(d) { return d.Periodtype;})
                    .key(function(d) { return d.Yr;})
                    .key(function(d) { return d.Period;})
                    .key(function(d) { return d.Dep;})
                    .rollup(function(d) { 
                            return {"Count":d3.sum(d, function(g) {return g.Count; }), "Beds":d3.sum(d, function(j) {return j.Beds;})};
                        }).entries(tstArray);

console.log(tstArray);

tstArray =  tstArray.map(function(d){
    var Periodtype = d.key
    var values1 = d.values.map(function(e){
        var Yr = e.key
        var values2 = e.values.map(function(f){
            var Period = f.key;
            var values3 = f.values.map(function(g){
                return{'Dep':g.key,Count':+g.values.Count,'Beds':+g.values.Beds}
            });
            return {'Period':Period,'values3':values3}
        });
        var tmparr = [];
        for (   var i = 0, len=values2.length; i < len; i++) {                                  
            for (   var j = 0, lenj=values2[i].values3.length; j < lenj; j++) {
                tmparr.push({    'Period':values2[i].Period,
                                 'Dep':values2[i].values3[j].Dep,
                                 'Count': +values2[i].values3[j].Count,
                                 'Beds': +values2[i].values3[j].Beds
                            });
             };  
         };

         return{'Year':Yar,'values2':tmparr}

      });
      return{'Periodtype':Periodtype,'values1':values1} })
                        ;

console.log(tstArray);

JsFiddle

Now, I have one solution, I think. I could just redo this for the lowest level (three more goes) but that seems to be a bad way to go about this. How can i get all the flattening in one go? I have tried but I have had little luck with values3. I still understand these concepts too shallowly. Help much appreciated.

Answer 1

Ok, after some help on which routes to explore I settled for a for-loop, mainly because the arrays are fixed and it was the easiest to get my head around.

var tmparr = [];
for (   var i = 0, len=values2.length; i < len; i++) {                                  
    for (   var j = 0, lenj=values2[i].values3.length; j < lenj; j++) {
       tmparr.push({    'Period':values2[i].Period,
                        'Dep':values2[i].values3[j].Dep,
                        'Count': +values2[i].values3[j].Count,
                        'Beds': +values2[i].values3[j].Beds
                   });
    };  
};

return{'Year':Yar,'values2':tmparr}

I then repeated this loop on the next level (I did this mainly for readability, by doing it this way I didn't have to nest more than two levels of for-loops).