count occurrences of two keys in objects in array

Question

I have the following array with objects and used the following code to creating a tally with the key "id":

var arr=[
{ id: 123, 
  title: "name1",
  status: "FAILED"
},
{
 id: 123,
 title: "name1", 
 status: "PASSED"
},
{
 id: 123,
 title: "name1",
 status: "PASSED"
},
{
 id: 123,
 title: "name1",
 status: "PASSED"
},
{
 id: 1234,
 title: "name2",
 status: "FAILED"
},
{
 id: 1234,
 title: "name2",
 status: "PASSED"
}

];


const test =arr.reduce((tally, item) => {
				
			  if (!tally[item.id]) {
				tally[item.id] = 1;
			  } else {
				tally[item.id] = tally[item.id] + 1;
			  }
			  return tally;
			}, {});
      
console.log(test);

Now what I want to do is to modify the tally to take in consideration the key status as well so the result will be somthing like:

[
{id:123, status:"PASSED", tally:3},
{id:123, status:"FAILED", tally:1},
{id:1234, status:"PASSED", tally:1},
{id:1234, status:"FAILED", tally:1}
]

Any idea? Thanks!

I would like the output to an array with objects as the example above . — Ali
– Ali, Commented Jul 3, 2018 at 11:19

baao · Accepted Answer · 2018-07-03 11:46:59Z

2

Just make the key item.id + item.status, then it's a simple assignment

const res = Object.values(arr.reduce((a, b) => {
  a[b.id + b.status] = Object.assign(b, {tally: (a[b.id + b.status] || {tally: 0}).tally + 1});
  return a;
}, {}));

console.log(res);

<script>
const arr=[
  { id: 123,
    title: "name1",
    status: "FAILED"
  },
  {
    id: 123,
    title: "name1",
    status: "PASSED"
  },
  {
    id: 123,
    title: "name1",
    status: "PASSED"
  },
  {
    id: 123,
    title: "name1",
    status: "PASSED"
  },
  {
    id: 1234,
    title: "name2",
    status: "FAILED"
  },
  {
    id: 1234,
    title: "name2",
    status: "PASSED"
  }

];
</script>

edited Jul 3, 2018 at 11:46

answered Jul 3, 2018 at 11:18

baao

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2 Comments

Ali Over a year ago

Thanx! I would like to keep the title but then didn't work got "TypeError: b is undefined"

baao Over a year ago

Edited the answer to keep the title in the result @Ali

ugrpla · Accepted Answer · 2018-07-03 11:26:08Z

1

here you go

const test = arr.reduce((acc, item) => {        
    let found = acc.find(obj => obj.id === item.id && obj.status === item.status)
    if (typeof found === "undefined") {
        item.tally = 1
        acc.push(item);
    } else {
        found.tally++;
    }
    return acc;
}, []);

answered Jul 3, 2018 at 11:26

ugrpla

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Comments

hsz · Accepted Answer · 2018-07-03 11:17:15Z

0

You should group your items first using key that will contain both id and status:

const result = arr.reduce((acc, item) => {
  const key = item.id + item.status;
  acc[key] = acc[key] || { ...item, tally: 0 };
  acc[key].tally++;
  return acc;
}, {});

console.log( Object.values(result) );

Output:

[
  { id: 123, title: 'name1', status: 'FAILED', tally: 1 },
  { id: 123, title: 'name1', status: 'PASSED', tally: 3 },
  { id: 1234, title: 'name2', status: 'FAILED', tally: 1 },
  { id: 1234, title: 'name2', status: 'PASSED', tally: 1 },
]

answered Jul 3, 2018 at 11:17

hsz

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Comments

amrender singh · Accepted Answer · 2018-07-03 11:20:35Z

Simply create a key with combination of id and status. And make a map using it. After that you can simply get the desired result from that. Try the following:

var arr=[{id:123,title:"name1",status:"FAILED"},{id:123,title:"name1",status:"PASSED"},{id:123,title:"name1",status:"PASSED"},{id:123,title:"name1",status:"PASSED"},{id:1234,title:"name2",status:"FAILED"},{id:1234,title:"name2",status:"PASSED"}];


const map =arr.reduce((tally, item) => {
	tally[item.id+"_"+item.status] = (tally[item.id+"_"+item.status] || 0) +1;
  return tally;
}, {});
      
const result = Object.keys(map).map((a)=>{ 
  var obj = {
      id : a.split("_")[0],
      status : a.split("_")[1],
      tally : map[a]
  };
  return obj;
});
      
console.log(result);

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