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How do I split an array of objects into multiple arrays of objects while filtering for duplicates?

Ok, tall order I know.

So here’s my situation, say I have the array of objects below

var fullData = [{foo1: bar1, foo2: bar2, foo3: bar3}, 
                {foo1: bar4, foo2: bar5, foo3: bar6}, 
                {foo1: bar7, foo2: bar8, foo3: bar6}]

I would like for this to be changed to

[{name: bar1, label: bar1}, {name: bar4, label: bar4},{name: bar7, label: bar7}]

[{name: bar2, label: bar2}, {name: bar5, label: bar5},{name: bar8, label: bar8}]

[{name: bar3, label: bar3}, {name: bar6, label: bar6}]

I have found the below from another thread that splits AoO to an object of Arrays.

var result = res.body.reduce((r, o) => {
                    Object.entries(o).forEach(([k, v]) => (r[k] = r[k] || []).push(v));
                    return r;
                }, Object.create(null));

But it does not filter for duplicates and does not format the data the way I labeled above, and I could not figure out how the function above is working. For duplicates I opted to use the _.uniq from lodash on each individual element of result but was stuck on the ‘name’ and ‘label’ formatting, so I thought I would ask much more experienced programmers than myself if there may be a way to incorporate all this into 1 function.

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Answer

You can just add check whether the array has the element before pushing it to the array, by changing this:

([k, v]) => (r[k] = r[k] || []).push(v)

to this:

r[k] = r[k] || []
if(!r[k].includes(v)) r[k].push(v)

var fullData = [{foo1: 'bar1', foo2: 'bar2', foo3: 'bar3'}, 
                {foo1: 'bar4', foo2: 'bar5', foo3: 'bar6'}, 
                {foo1: 'bar7', foo2: 'bar8', foo3: 'bar6'}]
                
var result = fullData.reduce((r, o) => {
   Object.entries(o).forEach(([k, v]) => {
      r[k] = r[k] || []
      if(!r[k].includes(v)) r[k].push(v)
   });
   return r;
 }, 
 Object.create(null));

console.log(result)

If you wish to flatten the result to be array of arrays, you can loop through entries of the previous result and push it into the new array

var fullData = [{foo1: 'bar1', foo2: 'bar2', foo3: 'bar3'}, 
                {foo1: 'bar4', foo2: 'bar5', foo3: 'bar6'}, 
                {foo1: 'bar7', foo2: 'bar8', foo3: 'bar6'}]
                
var tmpResult = fullData.reduce((r, o) => {
   Object.entries(o).forEach(([k, v]) => {
      r[k] = r[k] || []
      if(!r[k].includes(v)) r[k].push(v)
   });
   return r;
 }, 
 Object.create(null));

var result = [];
Object.keys(tmpResult).forEach(k => {
  result.push(
    tmpResult[k].map(v => ({name: k, value: v}))
  );
})
console.log(result)

I know that this seems inefficient, but I’m sure this is worth to try.

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