Sum Values Of Objects Based On Other Values In Object

I have an object, the format is such: let obj= { 'Jan 01': [ {dt: 'Jan 01', cat: 'abc', site: 'google', val1:10, val2:20, val3:30}, {dt: 'Jan 01', cat:

Solution 1:

Use dt+','+cat as a key in a Map to track dupes. sum up all the other keys.
assumes any keys other than site dt and cat are vals.

for(const key of Object.keys(obj)) {
  const catMap = new Map()
  for(const {site, dt, cat, ...vals} of obj[key]) {
    const row = catMap.get(dt+','+cat)||{dt, cat}
    Object.entries(vals).forEach(([k,v])=>row[k]=(row[k]||0)+v)
    catMap.set(dt+','+cat, row)
  }
  obj[key] = [...catMap.values()]
}

console.log(
  obj
)

<script>
let obj= {
  'Jan 01': [
             {dt: 'Jan 01', cat: 'abc', site: 'google', val1:10, val2:20, val3:30},
             {dt: 'Jan 01', cat: 'abc', site: 'bing', val1:23, val2:12, val3:14},
             {dt: 'Jan 01', cat: 'abc', site: 'jeeves', val1:67, val2:78, val3:12},
             {dt: 'Jan 01', cat: 'pqr', site: 'google', val1:10, val2:20, val3:30},
             {dt: 'Jan 01', cat: 'pqr', site: 'bing', val1:23, val2:12, val3:14},
             {dt: 'Jan 01', cat: 'pqr', site: 'jeeves', val1:67, val2:78, val3:12},
             {dt: 'Jan 01', cat: 'xyz', site: 'google', val1:10, val2:20, val3:30},
             {dt: 'Jan 01', cat: 'xyz', site: 'bing', val1:23, val2:12, val3:14},
             {dt: 'Jan 01', cat: 'xyz', site: 'jeeves', val1:67, val2:78, val3:12}
            ],
  'Feb 01': [
             {dt: 'Feb 01', cat: 'abc', site: 'google', val1:12, val2:11, val3:41},
             {dt: 'Feb 01', cat: 'abc', site: 'bing', val1:45, val2:67, val3:0},
             {dt: 'Feb 01', cat: 'abc', site: 'jeeves', val1:78, val2:34, val3:41},
             {dt: 'Feb 01', cat: 'pqr', site: 'google', val1:44, val2:88, val3:5},
             {dt: 'Feb 01', cat: 'pqr', site: 'bing', val1:56, val2:11, val3:99},
             {dt: 'Feb 01', cat: 'pqr', site: 'jeeves', val1:22, val2:34, val3:77},
             {dt: 'Feb 01', cat: 'xyz', site: 'google', val1:33, val2:99, val3:34},
             {dt: 'Feb 01', cat: 'xyz', site: 'bing', val1:77, val2:55, val3:14},
             {dt: 'Feb 01', cat: 'xyz', site: 'jeeves', val1:33, val2:23, val3:98}
            ],
  'Mar 01': [
             {dt: 'Mar 01', cat: 'abc', site: 'google', val1:11, val2:20, val3:6},
             {dt: 'Mar 01', cat: 'abc', site: 'bing', val1:22, val2:91, val3:89},
             {dt: 'Mar 01', cat: 'abc', site: 'jeeves', val1:33, val2:81, val3:12},
             {dt: 'Mar 01', cat: 'pqr', site: 'google', val1:44, val2:71, val3:33},
             {dt: 'Mar 01', cat: 'pqr', site: 'bing', val1:55, val2:61, val3:14},
             {dt: 'Mar 01', cat: 'pqr', site: 'jeeves', val1:66, val2:51, val3:43},
             {dt: 'Mar 01', cat: 'xyz', site: 'google', val1:77, val2:41, val3:98},
             {dt: 'Mar 01', cat: 'xyz', site: 'bing', val1:88, val2:31, val3:23},
             {dt: 'Mar 01', cat: 'xyz', site: 'jeeves', val1:99, val2:21, val3:4}
            ]
}
</script>

Solution 2:

Here is a different approach using reduce

  let objx= {
    'Jan 01': [
               {dt: 'Jan 01', cat: 'abc', site: 'google', val1:10, val2:20, val3:30},
               {dt: 'Jan 01', cat: 'abc', site: 'bing', val1:23, val2:12, val3:14},
               {dt: 'Jan 01', cat: 'abc', site: 'jeeves', val1:67, val2:78, val3:12},
               {dt: 'Jan 01', cat: 'pqr', site: 'google', val1:10, val2:20, val3:30},
               {dt: 'Jan 01', cat: 'pqr', site: 'bing', val1:23, val2:12, val3:14},
               {dt: 'Jan 01', cat: 'pqr', site: 'jeeves', val1:67, val2:78, val3:12},
               {dt: 'Jan 01', cat: 'xyz', site: 'google', val1:10, val2:20, val3:30},
               {dt: 'Jan 01', cat: 'xyz', site: 'bing', val1:23, val2:12, val3:14},
               {dt: 'Jan 01', cat: 'xyz', site: 'jeeves', val1:67, val2:78, val3:12}
              ],
              'Feb 01': [
                {dt: 'Feb 01', cat: 'abc', site: 'google', val1:12, val2:11, val3:41},
                {dt: 'Feb 01', cat: 'abc', site: 'bing', val1:45, val2:67, val3:0},
                {dt: 'Feb 01', cat: 'abc', site: 'jeeves', val1:78, val2:34, val3:41},
                {dt: 'Feb 01', cat: 'pqr', site: 'google', val1:44, val2:88, val3:5},
                {dt: 'Feb 01', cat: 'pqr', site: 'bing', val1:56, val2:11, val3:99},
                {dt: 'Feb 01', cat: 'pqr', site: 'jeeves', val1:22, val2:34, val3:77},
                {dt: 'Feb 01', cat: 'xyz', site: 'google', val1:33, val2:99, val3:34},
                {dt: 'Feb 01', cat: 'xyz', site: 'bing', val1:77, val2:55, val3:14},
                {dt: 'Feb 01', cat: 'xyz', site: 'jeeves', val1:33, val2:23, val3:98}
               ],
     'Mar 01': [
                {dt: 'Mar 01', cat: 'abc', site: 'google', val1:11, val2:20, val3:6},
                {dt: 'Mar 01', cat: 'abc', site: 'bing', val1:22, val2:91, val3:89},
                {dt: 'Mar 01', cat: 'abc', site: 'jeeves', val1:33, val2:81, val3:12},
                {dt: 'Mar 01', cat: 'pqr', site: 'google', val1:44, val2:71, val3:33},
                {dt: 'Mar 01', cat: 'pqr', site: 'bing', val1:55, val2:61, val3:14},
                {dt: 'Mar 01', cat: 'pqr', site: 'jeeves', val1:66, val2:51, val3:43},
                {dt: 'Mar 01', cat: 'xyz', site: 'google', val1:77, val2:41, val3:98},
                {dt: 'Mar 01', cat: 'xyz', site: 'bing', val1:88, val2:31, val3:23},
                {dt: 'Mar 01', cat: 'xyz', site: 'jeeves', val1:99, val2:21, val3:4}
               ]
            }

fo={}
  for(let o of Object.entries(objx)){
    fo[o[0]]=[]
     o[1].reduce((acc,curr,i)=>{
      return curr.dt==acc.dt && acc.cat==curr.cat? (acc= {...acc,...{...curr,['val1']:acc.val1+curr.val1, ['val2']:acc.val2+curr.val2, ['val3']:acc.val3+curr.val3}} 
           ,i!=o[1].length-1 ? acc : (delete acc.site  ,fo[o[0]].push(acc))): (delete acc.site,fo[o[0]].push(acc) , acc=curr)
    })
  }
 console.log(fo)