how to sum value children parent array sequently

Question

i have this kind of tree array, here is the actual data of my array https://pastebin.com/xtfpyKiE

there is id,parent_id, and value on each item,

id:1,
name:A,
value:0
   |
   ----id:2
       parent:1,
       name:B,
       value : 10
         |
         ------id:3,
               parent:2,
               name :C,
               value : 12
                  |
                   ------id:4,
                         parent:3,
                         name :D,
                         value : 14

how to sum the value by parent id, from the bottom child to the top parent,

so i can get the value of A : 36, value of B : 36, value of C : 26,

thank you,

Answer 1

You can use destructuring assignment to get nested properties of object and assign retrieved values to an array in sequence. Use a loop to .splice() two elements at a time from array to create object having A:36,B:36,C:26 pairs, push object back to array.

 const data = {id:1, name:"A", value:0 , parent:{id:2, name: "B", value: 10 , parent:{id:3, name: "C", value: 12 , parent:{id:4, name: "D", value: 14} } } }; let res = []; ({name:res[res.length], value:res[res.length] , parent:{ name:res[res.length], value:res[res.length] , parent:{ name:res[res.length], value:res[res.length] , parent:{ name:res[res.length], value:res[res.length]}}}} = data); let k = res.length / 2; while (res.length > k) { let [key, prop] = res.splice(0, 2); res.push({[key]:prop + (res[1] && !isNaN(res[1]) && res[1] || 0) + (res[3] && !isNaN(res[3]) && res[3] || 0) + (res[5] && !isNaN(res[5]) && res[5] || 0) }); } // A : 36, value of B : 36, value of C : 26 console.log(res)