Develop Reference

Format data for chart

I'm having some trouble formatting/transforming some simple data into a format that I can use to graph, and I'm hoping someone might help me solve. Currently, I have something like this
somedata=
{test1: {good: 3, bad: 2, redo: 2}}
{test2: {good: 4, bad: 3}}
{test3: {good: 3, redo: 4}}
into something like
series:
[{name: "good", data: [3,4,3]},
{name: "bad", data: [2,3,0]},
{name: "redo", data: [2,0,4]}]
I can grab the categories by using Object.keys(somedata) easy enough i.e. ['test1', 'test2', 'test3'] but having problem formatting the rest of the data. I tried something like
let combine = {};
Object.values(somedata).map((row) => {
for (const [key, value] of Object.entries(row)) {
combine.hasOwnProperty(key)
? combine[key].push(value)
: (combine[key] = [value]);
}
console.log("combined", combine);
});
but quickly realized that it won't add 0 when key doesn't exist, which is required for the chart to compare between the different series, such as bar charts. So, any help is appreciated.

You can first collect all unique values and then using array#reduce and other array methods generate all the values corresponding to each key in an object accumaltor.
const somedata = [{test1: {good: 3, bad: 2, redo: 2}}, {test2: {good: 4, bad: 3}}, {test3: {good: 3, redo: 4}}],
uniqueValues = [...new Set(
somedata.reduce((r,o) => {
Object.values(o).forEach(ob => {
r.push(...Object.keys(ob));
});
return r;
}, [])
)];
result = Object.values(somedata.reduce((r, o) => {
Object.values(o).forEach(ob => {
uniqueValues.forEach(k => {
r[k] = r[k] || { name: k, data: []};
ob[k] ? r[k].data.push(ob[k]): r[k].data.push(0);
});
});
return r;
},{}));
console.log(result);
.as-console-wrapper { max-height: 100% !important; top: 0; }

something like this: for each test, group categories (can optionally restrict to a subset) - assume Zero for missing category
const someData = {test1: {good: 3, bad: 2, redo: 2}, test2: {good: 4, bad: 3}, test3: {good: 3, redo: 4}};
function prepMyGraphData(data, fields) {
let out = {
}
for (const [k, el] of Object.entries(data)) {
const _fields = new Set((fields || Object.keys(el)).concat(Object.keys(out)));
for (const f of _fields) {
const v = el.hasOwnProperty(f) ? el[f] || 0 : 0 ; // own field or 0
if (out.hasOwnProperty(f)) {
out[f].data.push(v) // existing category
}else{
out[f] = {name: f, data: [v]} // new category entry
}
}
}
return Object.values(out)
}
let fields = ['good', 'bad', 'redo']; // OR, undefined, for ALL own properties
const data = prepMyGraphData(someData, fields);

Javascript flatten deeply nested Array with objects and renaming properties

I'm stuck again with some flattening and renaming of the following.
What I got:
test = [
{
date: '2020-03-30',
station: {
id: 0,
name: 'some description'
},
firstValues: [
{
result: 1,
type: 4,
max: 18,
min: 1,
},
{
result: 2,
type: 5,
max: 15,
min: 2,
}
],
lastValues: [
{
result: 1,
type: 3,
max: 17,
min: 1
},
{
result: 2,
type: 8,
max: 20,
min: 2
}
],
iD: 'xxx3',
count: 1
},
{
next object with same structure
}
]
What I try to achieve:
test = [
{
date: '2020-03-30',
station: 'some description',
first_E01_result: 1,
first_E01_type: 4,
first_E01_max: 18,
first_E01_min: 1,
first_E02_result: 2,
first_E02_type: 5,
first_E02_max: 15,
first_E02_min: 2,
last_E01_result: 1,
last_E01_type: 3,
last_E01_max: 17,
last_E01_min: 1,
last_E02_result: 2,
last_E02_type: 8,
last_E02_max: 20,
last_E02_min: 2,
iD: 'xxx3',
count: 1
},
{
next object with same structure
}
]
I'm quite aware that my approach isn't the right thing. I tried different things so far but couldn't get it working. I'm totally stuck again to find the right way because I do run into two main issues:
How can I make the difference between first and last values? (switch case or if and if else?)
and
How can I access the name property from the station object and assign it to the key of "station"
Here is my last approach which is still missing the right code for the mentioned problems:
convertTest(input) {
return input.map(obj => {
const obj1 = {};
const obj2 = {};
for (const prop in obj) {
if (obj.hasOwnProperty(prop) && Array.isArray(obj[prop])) {
for (let i = 0; i < obj[prop].length; i++) {
for (const [key, value] of Object.entries(obj[prop][i])) {
const name = 'first_EO' + (i + 1).toString() + '_' + key;
obj2[name] = value;
}
}
} else {
obj1[prop] = obj[prop];
}
const dataconverted = Object.assign({}, obj1, obj2);
return dataconverted;
}
});
}

You could take a recursive approach for all other nested objects except the first level with special cases.
var data = [{ date: '2020-03-30', station: { id: 0, name: 'some description' }, firstValues: [{ result: 1, type: 4, max: 18, min: 1 }, { result: 2, type: 5, max: 15, min: 2 }], lastValues: [{ result: 1, type: 3, max: 17, min: 1 }, { result: 2, type: 8, max: 20, min: 2 }], iD: 'xxx3', count: 1 }],
getPath = object => Object.entries(object).reduce((r, [k, v], i) => {
if (v && typeof v === 'object') {
r.push(...getPath(v).map(([left, right]) => [(Array.isArray(object) ? 'E' + (i + 1).toString().padStart(2, 0) : k) + '_' + left, right]));
} else {
r.push([k, v]);
}
return r;
}, []),
result = data.map(o => Object.fromEntries(Object.entries(o).reduce((r, [k, v]) => {
if (k === 'station') {
r.push([k, v.name]);
} else if (v && typeof v === 'object') {
if (k.endsWith('Values')) k = k.slice(0, -6);
r.push(...getPath(v).map(([left, right]) => [k + '_' + left, right]));
} else {
r.push([k, v]);
}
return r
}, [])));
console.log(result);
.as-console-wrapper { max-height: 100% !important; top: 0; }

You should use Map and Object.keys
var test = [{"date":"2020-03-30","station":{"id":0,"name":"some description"},"firstValues":[{"result":1,"type":4,"max":18,"min":1},{"result":2,"type":5,"max":15,"min":2}],"lastValues":[{"result":1,"type":3,"max":17,"min":1},{"result":2,"type":8,"max":20,"min":2}],"iD":"xxx3","count":1}]
console.log(flatten(test));
function flatten(arr) {
return arr.map(el => ModifyObject(el))
}
function ModifyObject(el) {
const obj = {};
obj.date = el.date;
obj.iD = el.iD;
obj.count = el.count;
obj.station = el.station.name;
flattenObjectByProperty(obj, el, 'firstValues')
flattenObjectByProperty(obj, el, 'lastValues')
return obj;
}
function flattenObjectByProperty(obj, el, property) {
(el[property] || []).map((child, i) => {
Object.keys(child).forEach(key => {
obj[property + '_E' + i + '_' + key] = child[key]
});
});
}

Please try this.
test = test.map((elem) => {
elem.firstValues.forEach((child, index) => {
for(let key in child){
let v = `first_E${index+1}_${key}`
elem[v] = child[key];
}
})
elem.lastValues.forEach((child, index) => {
for(let key in child){
let v = `last_E${index+1}_${key}`
elem[v] = child[key];
}
})
elem['station'] = elem.station.name;
delete elem.firstValues;
delete elem.lastValues;
return elem;
})

You can use Array.prototype.reduce to flatten as per your requirement
const test = [
{
date: '2020-03-30',
station: {
id: 0,
name: 'some description'
},
firstValues: [
{
result: 1,
type: 4,
max: 18,
min: 1,
},
{
result: 2,
type: 5,
max: 15,
min: 2,
}
],
lastValues: [
{
result: 1,
type: 3,
max: 17,
min: 1
},
{
result: 2,
type: 8,
max: 20,
min: 2
}
],
iD: 'xxx3',
count: 1
}
];
const result = test.reduce((acc, curr) => {
const { firstValues, lastValues, ...rest } = curr;
const modifiedFirstValues = firstValues.reduce((r, c, i) => {
Object.entries(c).forEach(([key, value]) => {
const modifiedKey = `first_E${i + 1}_${key}`;
r[modifiedKey] = value;
});
return r;
}, Object.create(null));
const modifiedLastValues = lastValues.reduce((r, c, i) => {
Object.entries(c).forEach(([key, value]) => {
const modifiedKey = `last_E${i + 1}_${key}`;
r[modifiedKey] = value;
});
return r;
}, Object.create(null));
const finalObj = {
...rest,
...modifiedFirstValues,
...modifiedLastValues
};
acc.push(finalObj);
return acc;
}, []);
console.log(result);

How to create Object with nested Objects from an Array

I have an array [1, 2, 3] and I want to transfer it to object with nested parent-child objects's series like this :
{ value: 1, rest: { value: 2, rest: { value: 3, rest: null } }
If I have an array [1, 2, 3, 4] the result will be like this :
{ value: 1, rest: { value: 2, rest: { value: 3, rest: { value:4, rest:null } }
The best effort of me is this snippet of code :
const arrayToList = (array) => {
let list = { value: null, rest: null };
for (let e of array) {
array.indexOf(e) === 0 && (list.value = e);
array.indexOf(e) >= 1 && (list.rest = { value: e });
}
return list;
};
console.log(arrayToList([1, 2, 3]));

You can use reduceRight like so:
let obj = arr.reduceRight((rest, value) => ({ value, rest }), null);
It starts building the object from the inside out; it starts by creating the innermost object and then it uses that object as the rest property for the next outer object and so on until there are no more items in the array.
Demo:
let obj = [1, 2, 3, 4].reduceRight((rest, value) => ({ value, rest }), null);
console.log(obj);

You can create such object by running below recursive function:
let arr = [1, 2, 3, 4];
let transform = (arr, obj) => {
if(arr.length === 0){
return obj;
} else {
let last = arr[arr.length - 1];
let newArr = arr.slice(0, arr.length - 1);
return transform(newArr, { value: last, rest: obj || null })
}
};
console.log(transform(arr));

Use a recursive function:
let array = [1, 2, 3];
function arrayToL(array) {
let el = array.splice(0, 1)[0];
let rtn = {
value: el
}
rtn.rest = (array.length > 0) ? arrayToL(array) : null;
return rtn;
}
console.log(arrayToL(array));

I suggest another solution using the spread operator and reversing the array and start building object from the array end :
let arr = [1, 2, 4, 5]
let obj = {} //object to be built
arr.slice().reverse().forEach(item => { //i used the slice method
//in order to avoid mutating
//the original variable
obj = { ...obj,
...{
value: item,
rest: obj
}
};
})
console.log(obj)

update nested json object using recursion in JavaScript

I'm trying to create an updated object from an existing object.
The sample object is:
// sample object
const testObj = {
a: 1,
b: {
c: 2,
d: {
e: 3,
f: {
g: 4
}
}
}
};
I want to create a new object from the above object with some concatenation of each value:
// expected object
const expectedObject= {
a: '1 a',
b: {
c: '2 a',
d: {
e: '3 a',
f: {
g: '4 a'
}
}
}
};
here is my sample code:
let expectedObject = {};
const newObject = object => {
Object.entries(object).forEach(([key, value]) => {
if (typeof value === "object") {
Object.keys(value).map(key => {
value[key] = value[key] + " a";
return value;
});
expectedObject[key] = value;
//return newTest;
} else {
expectedObject[key] = value;
return expectedObject;
}
});
return expectedObject;
};
console.log(newObject(testObj));
the outcome in console is:
{a: 1, b: {…}}
a: 1
b:
c: "2 a"
d: "[object Object] a"
__proto__: Object
__proto__: Object
I wanted to use recursion here and also tried it but no luck.
any help, thanks?

You could get a new object my mapping changed values and creating new objects.
function map(object, fn) {
return Object.fromEntries(Object
.entries(object)
.map(([k, v]) => [k, v && typeof v === 'object' ? map(v, fn) : fn(v)])
);
}
var object = { a: 1, b: { c: 2, d: { e: 3, f: { g: 4 } } } },
result = map(object, v => v + ' a');
console.log(result);
If you have arrays inside, you could add a check in advance and map the values.
const
map = fn => {
const iter = v => v && typeof v === 'object'
? Array.isArray(v)
? v.map(iter)
: Object.fromEntries(Object.entries(v).map(([k, v]) => [k, iter(v, fn)]))
: fn(v);
return iter;
};
var object = { a: 1, b: { c: 2, d: { e: 3, f: { g: 4, k: [5, 6] } } } },
addA = map(v => v + ' a'),
result = addA(object);
console.log(result);

This is simply a refactoring of the answer from #user633183. I like that approach a lot, but think it can be simplified by extracting two more reusable functions. This started as a comment on that answer, but I thought it would be better to be explicit.
const map = (f) => (a) =>
a.map(f)
const mapObj = (f) => (o) =>
Object .entries (o) .reduce ( (a, [k, v] ) => ({ ...a, [k]: f(v) }), {})
const traverse = (f) => (t) =>
Array.isArray(t)
? map (traverse (f)) (t)
: Object(t) === t
? mapObj (traverse (f)) (t)
: f (t)
const input =
{ a: [ 1, 11, 111 ], b: { c: 2, d: { e: [ 3, { f: { g: 4 } } ] } } }
const output =
traverse(x => `${x} a`) (input)
console.log(output)
mapObj can be written in many different ways. Here are two alternatives:
const mapObj = (f = identity) => (o = {}) =>
Object .fromEntries (Object .entries (o) .map (([ k, v ]) => [ k, f (v) ]))
const mapObj = (f = identity) => (o = {}) =>
Object .assign .apply (null, Object .entries (o) .map (([ k, v ]) => ({ [k]: f (v)

Here's an approach using a modification of the original code to demonstrate what needed to be changed in order to make it work. You had some things switched up reading the value and setting the new one. Also I'm using the spread operator to clone the object before modifying it.
const testObj = {
a: 1,
b: {
c: 2,
d: {
e: 3,
f: {
g: 4
}
}
}
};
const newObject = object => {
const clonedObj = { ...object };
const entries = Object.entries(clonedObj);
entries.forEach(([key, value]) => {
if (typeof value === "object") {
clonedObj[key] = newObject(value);
} else {
clonedObj[key] = value + " a";
}
});
return clonedObj;
};
console.log(newObject(testObj));
console.log(testObj); // prove that the original object hasn't changed

Here's a simple recursive technique. It is similar to Nina's but it preserves arrays, if present in the structure.
If the input, t, is an array, create a new array by traversing each array value, v, with the traversing function, f
(inductive) Otherwise t is not an array. If t is an object, create a new object from key value pairs, [ k, v ], by traversing each value, v, with the traversing function, f
(inductive) Otherwise t is not an array and t is not an object. This means t is either a primitive value, such as string, number, or null
Numbered comments below correspond to the explanation above -
const identity = x =>
x
const traverse = (f = identity, t = {}) =>
Array.isArray(t) // 1
? Array.from(t, v => traverse(f, v))
: Object(t) === t // 2
? Object.fromEntries(Object.entries(t).map(([ k, v ]) => [ k, traverse(f, v) ]))
: f (t) // 3
const input =
{ a: [ 1, 11, 111 ], b: { c: 2, d: { e: [ 3, { f: { g: 4 } } ] } } }
const output =
traverse(x => `${x} a`, input)
console.log(output)

Here is a solution using object-scan. It works by building the solution at the same time as the input is traversed.
// const objectScan = require('object-scan');
const testObj = { a: 1, b: { c: 2, d: { e: 3, f: { g: 4 } } } };
const cloneAndModify = (obj) => objectScan(['**'], {
breakFn: ({ property, value, isLeaf, context }) => {
if (property === undefined) {
return;
}
const ref = context[context.length - 1];
if (!(property in ref)) {
ref[property] = isLeaf ? `${value} a` : {};
}
context.push(ref[property]);
},
filterFn: ({ context }) => {
context.pop();
}
})(obj, [{}])[0];
const r = cloneAndModify(testObj);
console.log(r);
// => { b: { d: { f: { g: '4 a' }, e: '3 a' }, c: '2 a' }, a: '1 a' }
.as-console-wrapper {max-height: 100% !important; top: 0}
<script src="https://bundle.run/object-scan#13.7.1"></script>
Disclaimer: I'm the author of object-scan

Key value pair intersection of an array of objects

I would like to know if there is a way to find the intersection of a key value pair in an array of objects. Let's say you have an array of three objects which all have the same keys like this :
arrayOfObj = [
{
"a": 1,
"b": "stringB"
"c": {"c1":1,
"c2": "stringC2"
}
},
{
"a": 1,
"b": "stringBdiff"
"c": {"c1":1,
"c2": "stringC2"
}
},
{
"a": 1,
"b": "stringB"
"c": {"c1":1,
"c2": "stringC2"
}
}
]
I would like to find the common key value pairs of the three objects:
output= [
{"a":1},
{"c": {"c1":1,
"c2":"stringC2"
}
}
]
This is what I have done so far, it works but not on nested objects. I would like to know if there is a more elegant way to do it and one that could work on nested object as well.
let properties;
let commonFound = false;
let notCommonFound = false;
const commonValues = [];
let value;
const initialArray = [{
"a": 2,
"b": "stringB",
"c": {
"c1": 1,
"c2": "stringC2"
}
},
{
"a": 1,
"b": "stringB",
"c": {
"c1": 2,
"c2": "stringC2"
}
},
{
"a": 1,
"b": "stringB",
"c": {
"c1": 2,
"c2": "stringC2"
}
}
];
const commonStorage = [];
const reference = initialArray[0];
properties = Object.keys(reference);
properties.forEach((property) => {
for (let i = 0; i < initialArray.length; i++) {
commonFound = false;
notCommonFound = false;
for (let j = 0; j <i ; j++) {
if (initialArray[i][property] === initialArray[j][property]) {
commonFound = true;
value = initialArray[i][property];
}
else {
notCommonFound = true;
value = [];
}
}
}
if (commonFound && !notCommonFound) {
commonStorage.push({[property] : value});
}
});
console.log(commonStorage);

Before we implement intersect we'll first look at how we expect it to behave –
console.log
( intersect
( { a: 1, b: 2, d: 4 }
, { a: 1, c: 3, d: 5 }
)
// { a: 1 }
, intersect
( [ 1, 2, 3, 4, 6, 7 ]
, [ 1, 2, 3, 5, 6 ]
)
// [ 1, 2, 3, <1 empty item>, 6 ]
, intersect
( [ { a: 1 }, { a: 2 }, { a: 4, b: 5 }, ]
, [ { a: 1 }, { a: 3 }, { a: 4, b: 6 }, ]
)
// [ { a: 1 }, <1 empty item>, { a: 4 } ]
, intersect
( { a: { b: { c: { d: [ 1, 2 ] } } } }
, { a: { b: { c: { d: [ 1, 2, 3 ] } } } }
)
// { a: { b: { c: { d: [ 1, 2 ] } } } }
)
Challenging problems like this one are made easier by breaking them down into smaller parts. To implement intersect we will plan to merge two calls to intersect1, each contributing one side of the computed result –
const intersect = (left = {}, right = {}) =>
merge
( intersect1 (left, right)
, intersect1 (right, left)
)
Implementing intersect1 is remains relatively complex due to the need to support both objects and arrays – the sequence of map, filter, and reduce helps maintain a flow of the program
const intersect1 = (left = {}, right = {}) =>
Object.entries (left)
.map
( ([ k, v ]) =>
// both values are objects
isObject (v) && isObject (right[k])
? [ k, intersect (v, right[k]) ]
// both values are "equal"
: v === right[k]
? [ k, v ]
// otherwise
: [ k, {} ]
)
.filter
( ([ k, v ]) =>
isObject (v)
? Object.keys (v) .length > 0
: true
)
.reduce
( assign
, isArray (left) && isArray (right) ? [] : {}
)
Lastly we implement merge the same way we did in the other Q&A –
const merge = (left = {}, right = {}) =>
Object.entries (right)
.map
( ([ k, v ]) =>
isObject (v) && isObject (left [k])
? [ k, merge (left [k], v) ]
: [ k, v ]
)
.reduce (assign, left)
The final dependencies –
const isObject = x =>
Object (x) === x
const isArray =
Array.isArray
const assign = (o, [ k, v ]) =>
(o [k] = v, o)
Verify the complete program works in your browser below –
const isObject = x =>
Object (x) === x
const isArray =
Array.isArray
const assign = (o, [ k, v ]) =>
(o [k] = v, o)
const merge = (left = {}, right = {}) =>
Object.entries (right)
.map
( ([ k, v ]) =>
isObject (v) && isObject (left [k])
? [ k, merge (left [k], v) ]
: [ k, v ]
)
.reduce (assign, left)
const intersect = (left = {}, right = {}) =>
merge
( intersect1 (left, right)
, intersect1 (right, left)
)
const intersect1 = (left = {}, right = {}) =>
Object.entries (left)
.map
( ([ k, v ]) =>
isObject (v) && isObject (right[k])
? [ k, intersect (v, right[k]) ]
: v === right[k]
? [ k, v ]
: [ k, {} ]
)
.filter
( ([ k, v ]) =>
isObject (v)
? Object.keys (v) .length > 0
: true
)
.reduce
( assign
, isArray (left) && isArray (right) ? [] : {}
)
console.log
( intersect
( { a: 1, b: 2, d: 4 }
, { a: 1, c: 3, d: 5 }
)
// { a: 1 }
, intersect
( [ 1, 2, 3, 4, 6, 7 ]
, [ 1, 2, 3, 5, 6 ]
)
// [ 1, 2, 3, <1 empty item>, 6 ]
, intersect
( [ { a: 1 }, { a: 2 }, { a: 4, b: 5 }, ]
, [ { a: 1 }, { a: 3 }, { a: 4, b: 6 }, ]
)
// [ { a: 1 }, <1 empty item>, { a: 4 } ]
, intersect
( { a: { b: { c: { d: [ 1, 2 ] } } } }
, { a: { b: { c: { d: [ 1, 2, 3 ] } } } }
)
// { a: { b: { c: { d: [ 1, 2 ] } } } }
)
intersectAll
Above intersect only accepts two inputs and in your question you want to compute the intersect of 2+ objects. We implement intersectAll as follows -
const None =
Symbol ()
const intersectAll = (x = None, ...xs) =>
x === None
? {}
: xs .reduce (intersect, x)
console.log
( intersectAll
( { a: 1, b: 2, c: { d: 3, e: 4 } }
, { a: 1, b: 9, c: { d: 3, e: 4 } }
, { a: 1, b: 2, c: { d: 3, e: 5 } }
)
// { a: 1, c: { d: 3 } }
, intersectAll
( { a: 1 }
, { b: 2 }
, { c: 3 }
)
// {}
, intersectAll
()
// {}
)
Verify the results in your browser –
const isObject = x =>
Object (x) === x
const isArray =
Array.isArray
const assign = (o, [ k, v ]) =>
(o [k] = v, o)
const merge = (left = {}, right = {}) =>
Object.entries (right)
.map
( ([ k, v ]) =>
isObject (v) && isObject (left [k])
? [ k, merge (left [k], v) ]
: [ k, v ]
)
.reduce (assign, left)
const intersect = (left = {}, right = {}) =>
merge
( intersect1 (left, right)
, intersect1 (right, left)
)
const intersect1 = (left = {}, right = {}) =>
Object.entries (left)
.map
( ([ k, v ]) =>
isObject (v) && isObject (right[k])
? [ k, intersect (v, right[k]) ]
: v === right[k]
? [ k, v ]
: [ k, {} ]
)
.filter
( ([ k, v ]) =>
isObject (v)
? Object.keys (v) .length > 0
: true
)
.reduce
( assign
, isArray (left) && isArray (right) ? [] : {}
)
const None =
Symbol ()
const intersectAll = (x = None, ...xs) =>
x === None
? {}
: xs .reduce (intersect, x)
console.log
( intersectAll
( { a: 1, b: 2, c: { d: 3, e: 4 } }
, { a: 1, b: 9, c: { d: 3, e: 4 } }
, { a: 1, b: 2, c: { d: 3, e: 5 } }
)
// { a: 1, c: { d: 3 } }
, intersectAll
( { a: 1 }
, { b: 2 }
, { c: 3 }
)
// {}
, intersectAll
()
// {}
)
remarks
You'll want to consider some things like –
intersect
( { a: someFunc, b: x => x * 2, c: /foo/, d: 1 }
, { a: someFunc, b: x => x * 3, c: /foo/, d: 1 }
)
// { d: 1 } (actual)
// { a: someFunc, c: /foo/, d: 1 } (expected)
We're testing for what's considered equal here in intersect1 –
const intersect1 = (left = {}, right = {}) =>
Object.entries (left)
.map
( ([ k, v ]) =>
isObject (v) && isObject (right[k])
? [ k, intersect (v, right[k]) ]
: v === right[k] // <-- equality?
? [ k, v ]
: [ k, {} ]
)
.filter
( ...
If we want to support things like checking for equality of Functions, RegExps, or other objects, this is where we would make the necessary modifications
recursive diff
In this related Q&A we compute the recursive diff of two objects