How to traversed object of two arrays as following output in JavaScript

Question

I have two object of arrays, i want to process it as following output

var parts={"Glenn": [12,22,32],
"Ryan": [13,23,33],
"Steve K": [14],
"Jerom":[15,25,35],
};

var labor={
"Glenn": [12,22,32],
"Ryan": [13,23,33],
"Steve K": [14],
"Nike":[16,26,36]
};

//Target output   
[{person:"Glenn",count:6},
{person:"Ryan",count:6},
{person:"Steve K",count:2},
{person:"Jerom",count:3},
{person:"Nike",count:3}
];

Here count means the length of array regards to key and person is the key,If keys are matched then add their array length and assign it to count and key appear as person, if no match then just copy it to new array.Please help me how to achieve above array objects

score 2 · Accepted Answer · answered Apr 02 '20 at 11:54

2

Combine the two arrays and reduce them.

This should work:

var parts = {
  "Glenn": [12, 22, 32],
  "Ryan": [13, 23, 33],
  "Steve K": [14],
  "Jerom": [15, 25, 35],
};

var labor = {
  "Glenn": [12, 22, 32],
  "Ryan": [13, 23, 33],
  "Steve K": [14],
  "Nike": [16, 26, 36]
};

const combined = [...Object.entries(parts), ...Object.entries(labor)];
const result = combined.reduce((res, curr) => {
  const existing = res.find(e => e.person === curr[0]);
  if (existing) {
    existing.count += curr[1].length;
  } else {
    res.push({
      person: curr[0],
      count: curr[1].length
    })
  }
  return res;
}, []);

answered Apr 02 '20 at 11:54

Roberto Zvjerković

9,657
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Hi,I have tried this course in Node.js then working fine but in Angular i gor error like "Property 'entries' does not exist on type 'ObjectConstructor'" – Sherin Green Apr 02 '20 at 14:30
https://stackoverflow.com/questions/45422573/property-entries-does-not-exist-on-type-objectconstructor – Roberto Zvjerković Apr 02 '20 at 14:31
I have updated it to ES2017 but there is some error associated with curr[1].length Property 'length' does not exist on type '{}' – Sherin Green Apr 02 '20 at 14:39
You're doing something wrong, `curr[1]` is an array. – Roberto Zvjerković Apr 02 '20 at 14:59

score 1 · Answer 2 · answered Apr 02 '20 at 12:03

You can create a set of all the unique keys from both objects, then iterate over that set producing a result object from the lengths of the corresponding elements from the parts and labor object:

var parts = {
  "Glenn": [12, 22, 32],
  "Ryan": [13, 23, 33],
  "Steve K": [14],
  "Jerom": [15, 25, 35],
};

var labor = {
  "Glenn": [12, 22, 32],
  "Ryan": [13, 23, 33],
  "Steve K": [14],
  "Nike": [16, 26, 36]
};

let keys = new Set([...Object.keys(parts), ...Object.keys(labor)]);
let result = {}
keys.forEach(k => result[k] = (result[k] || 0) + (parts[k] || []).length + (labor[k] || []).length);
console.log(result);

score 0 · Answer 3 · answered Apr 02 '20 at 11:52

Refer to the following code that makes use of the for...in loop:

var parts = {
    Glenn: [12, 22, 32],
    Ryan: [13, 23, 33],
    "Steve K": [14],
    Jerom: [15, 25, 35]
};
var labor = {
    Glenn: [12, 22, 32],
    Ryan: [13, 23, 33],
    "Steve K": [14],
    Nike: [16, 26, 36]
};
var counts = {};
// iterate through the parts and keep count
for (let key in parts) {
    if (key in counts) {
        counts[key] += parts[key].length;
    } else {
        counts[key] = parts[key].length;
    }
}
// iterate through the labor and keep count
for (let key in labor) {
    if (key in counts) {
        counts[key] += labor[key].length;
    } else {
        counts[key] = labor[key].length;
    }
}
var res = [];
// iterate through the counts and convert to an array
for (let key in counts) {
    res.push({
        person: key,
        count: counts[key]
    })
}

My target output is //Target output [{person:"Glenn",count:6}, {person:"Ryan",count:6}, {person:"Steve K",count:2}, {person:"Jerom",count:3}, {person:"Nike",count:3} ]; When i run this code ,i didn't get {person:"Jerom",count:3}, {person:"Nike",count:3} — Sherin Green, Apr 03 '20 at 03:48

score 0 · Answer 4 · answered Apr 02 '20 at 12:49

Iterate both arrays to find the occurences and then increment the count

var parts = {
Glenn: [12, 22, 32],
Ryan: [13, 23, 33],
"Steve K": [14],
Jerom: [15, 25, 35]
};

var labor = {
Glenn: [12, 22, 32],
Ryan: [13, 23, 33],
"Steve K": [14],
Nike: [16, 26, 36]
};

var arr = [];
for (let [key, value] of Object.entries(parts)) {
arr.push({
    person: key,
    count: value.length
});
}
for (let [key, value] of Object.entries(labor)) {
const found = arr.find(elem => elem.person === key);
if (found) {
    found.count += value.length;
} else {
    arr.push({
        person: key,
        count: value.length
    });
}
}
console.log(arr);

How to traversed object of two arrays as following output in JavaScript

4 Answers4