I got stuck on a maybe simple task, but could not find any solution.
I have some JSON Data - lets say:
[{
"_id": 1,
"type": "person",
"Name": "Hans",
"WorksFor": ["3", "4"]
}, {
"_id": 2,
"type": "person",
"Name": "Michael",
"WorksFor": ["3"]
}, {
"_id": 3,
"type": "department",
"Name": "Marketing"
}, {
"_id": 4,
"type": "department",
"Name": "Sales"
}]
As I learned here it is quite simple to get all the persons and the departments they work for together using a map array for the departments.
Then I can map the corresponding department to the Person and receive something like:
[{
"_id": 1,
"type": "person",
"Name": "Hans",
"WorksFor": ["3", "4"],
"Readable": ["Marketing", "Sales"]
}, {
"_id": 2,
"type": "person",
"Name": "Michael",
"WorksFor": ["3"],
"Readable": ["Sales"]
}]
But for another interface I need the data "the other way round" e.g.
[{
"_id": 3,
"type": "department",
"Name": "Marketing",
"employees": [
"Hans", "Michael"
]
}, {
"_id": 4,
"type": "department",
"Name": "Sales",
"employees": [
"Hans"
]
}]
Is there any decent way to achieve this structure? Two days of trying didn't get me anywhere...
var data = [{ "_id": 1, "type": "person", "Name": "Hans", "WorksFor": ["3", "4"] }, { "_id": 2, "type": "person", "Name": "Michael", "WorksFor": ["3"] }, { "_id": 3, "type": "department", "Name": "Marketing" }, { "_id": 4, "type": "department", "Name": "Sales" }];
var departments = [],
persons = [];
data.forEach(e => {
if (e.type === "person") {
persons.push(e);
} else if (e.type === "department") {
departments.push(e);
e.employees = [];
}
});
departments.forEach(d => {
var workers = persons.filter(p => p.WorksFor.indexOf(d._id.toString()) > -1)
/*.map(p => p.Name)*/ // add this if you only need the name instead of the complete "person"
d.employees = d.employees.concat(workers);
});
console.log(JSON.stringify(departments, null, 4));
You can try something like this:
var data = [{ "_id": 1, "type": "person", "Name": "Hans", "WorksFor": ["3", "4"]}, { "_id": 2, "type": "person", "Name": "Michael", "WorksFor": ["3"]}, { "_id": 3, "type": "department", "Name": "Marketing"}, { "_id": 4, "type": "department", "Name": "Sales"}]
var ignoreDept = ['person'];
var result = data.reduce(function(p,c,i,a){
if(ignoreDept.indexOf(c.type) < 0){
c.employees = a.reduce(function(arr,emp){
if(emp.WorksFor && emp.WorksFor.indexOf(c._id.toString()) > -1){
arr.push(emp.Name)
}
return arr;
},[]);
p.push(c);
}
return p;
}, []);
console.log(result)
The solution using Array.prototype.filter() and Array.prototype.forEach() functions:
var data = [{ "_id": 1, "type": "person", "Name": "Hans", "WorksFor": ["3", "4"]}, { "_id": 2, "type": "person", "Name": "Michael", "WorksFor": ["3"]}, { "_id": 3, "type": "department", "Name": "Marketing"}, { "_id": 4, "type": "department", "Name": "Sales"}],
// getting separated "lists" of departments and employees(persons)
deps = data.filter(function(o){ return o.type === "department"; }),
persons = data.filter(function(o){ return o.type === "person"; });
deps.forEach(function (d) {
d['employees'] = d['employees'] || [];
persons.forEach(function (p) {
if (p.WorksFor.indexOf(String(d._id)) !== -1) { // check the `id` coincidence between the employee and the department
d['employees'].push(p.Name);
}
});
});
console.log(deps);
You could use a hash table and a single loop for each array.
Methods:
Array#reduce for iterating an array and returning the result,
Array#forEach for looping the inner array WorksFor,
Object.create(null) to generate an object without any prototypes,
some other pattern, like a closure over hash and
the use of logical OR || for checking a falsy value and taking an object as default.
hash[b] = hash[b] || { _id: b, employees: [] };
var data = [{ _id: 1, type: "person", Name: "Hans", WorksFor: [3, 4] }, { _id: 2, type: "person", Name: "Michael", WorksFor: [3] }, { _id: 3, type: "department", Name: "Marketing" }, { _id: 4, type: "department", Name: "Sales" }],
result = data.reduce(function (hash) {
return function (r, a) {
if (a.type === 'person') {
a.WorksFor.forEach(function (b) {
hash[b] = hash[b] || { _id: b, employees: [] };
hash[b].employees.push(a.Name);
});
}
if (a.type === 'department') {
hash[a._id] = hash[a._id] || { _id: b, employees: [] };
hash[a._id].type = a.type;
hash[a._id].Name = a.Name;
r.push(hash[a._id]);
}
return r;
};
}(Object.create(null)), []);
console.log(result);
.as-console-wrapper { max-height: 100% !important; top: 0; }
Here's a way you can get the first mapping. I've added some comments so you can follow along, and with it I hope you can find the answer to your second problem.
// First, let's get just the items in this array that identify persons
// I've called this array "data"
data.filter(x => x.type === 'person')
// Now let's map over them
.map(person =>
// We want all of the data associated with this person, so let's
// use Object.assign to duplicate that data for us
Object.assign({}, person, {
// In addition, we want to map the ID of the WorksFor array to the Name
// of the corresponding department. Assuming that the _id key is unique,
// we can due this simply by mapping over the WorksFor array and finding
// those values within the original array.
Readable: person.WorksFor.map(wfId =>
// Notice here the parseInt. This will not work without it due to
// the type difference between WorksFor (string) and _id (integer)
data.find(d => d._id === parseInt(wfId)).Name
)
})
);
var data = [{ "_id": 1, "type": "person", "Name": "Hans", "WorksFor": ["3", "4"]}, { "_id": 2, "type": "person", "Name": "Michael", "WorksFor": ["3"]}, { "_id": 3, "type": "department", "Name": "Marketing"}, { "_id": 4, "type": "department", "Name": "Sales"}];
var dep = {};
data.forEach(e => (e.type === 'person' && e.WorksFor.forEach(d => dep[d]? dep[d].push(e.Name): dep[d] = [e.Name])));
data.forEach(e => (e.type == 'department' && (e.employees = dep[e._id] || [])));
data = data.filter(e => e.type == 'department');
console.log(data);
Related
I am trying to change the value of object from the array but, it's not work as expected. I tried following.
const arrObj = [
{
"label": "test1",
"value": 123,
"type": "number",
"field": {
"label": "another",
"description": "abcd"
}
},
{
"label": "test2",
"value": 111,
"type": "number"
},
]
arrObj.forEach(obj => {
obj = {...obj, ...obj.field}
delete obj.field
})
console.log("after:", arrObj);
Also I found some solution that to use index but, it add index before the object.
const arrObj = [
{
"label": "test1",
"value": 123,
"type": "number",
"field": {
"label": "abcd",
"description": "abcd"
}
},
{
"label": "test2",
"value": 111,
"type": "number"
}
]
arrObj.forEach((obj, index) => {
obj[index] = {...obj, ...obj.field}
delete obj.field
})
console.log("after:", arrObj);
How can I do with forEach?
Edit:
I want to remove the field object and assign/overwrite all the property outside.
Using map and assigning the result is probably a better way of doing this, but if you want to use forEach, you need to assign to the original array inside the loop:
const arrObj = [
{
"label": "test1",
"value": 123,
"type": "number",
"field": {
"label": "another",
"description": "abcd"
}
},
{
"label": "test2",
"value": 111,
"type": "number"
},
]
arrObj.forEach(({ field, ...rest}, idx, orig) => {
orig[idx] = { ...rest, ...field }
})
console.log(arrObj);
I would use map to change an array, but you may have a reason that you wish to modify the original. You could just reassign arrObj to the output of the map.
const arrObj = [
{
"label": "test1",
"value": 123,
"type": "number",
"field": {
"label": "another",
"description": "abcd"
}
},
{
"label": "test2",
"value": 111,
"type": "number"
},
]
const newArr = arrObj.map(( obj ) => {
const {field, ...rest} = obj
return {...field, ...rest}
})
console.log("after:", newArr);
I need inner join with two array in javascript like this:
array1 =
[
{
"id": 1,
"name": "Tufan"
},
{
"id": 2,
"name": "Batuhan"
},
{
"id": 3,
"name": "Hasan"
}
]
array2 =
[
{
"name": "yyy",
"externalid": "1",
"value": "Asd"
},
{
"name": "aaaa"
"externalid": "2",
"value": "ttt"
}
]
expectedArray =
[
{
"id": 1,
"name": "Tufan",
"externalid": "1",
"value": "Asd"
},
{
"id": 2,
"name": "Batuhan",
"externalid": "2",
"value": "ttt"
}
]
rules:
on: array2.externalid = array1.id
select: array1.id, array1.name, array2.externalid, array2.value
My approach:
array1.filter(e => array2.some(f => f.externalid == e.id));
// I need help for continue
How can I make this?
Doesn't matter information: I use ES5 and pure javascript
You can do it like this:
const res = array2.map((item) => {
const related = array1.find((el) => el.id == item.externalid);
return { ...item, ...related };
});
Using a map to loop over the array2 and a find to get the array1 relative.
Array One:
array1 = [{
"id": 1,
"name": "aaaaa",
"attr": [{"attr_code": "a_id", "value": "5"}]
},
{
"id": 2,
"name": "bbbbb",
"attr": [{"attr": "a_id", "value": "4"}]
}]
Array Two:
array2 = [{
"id": 4,
"name": "bef",
},
{
"id": 5,
"name": "bcd",
}]
Resulting Array:
resultingArray = [{
"id": 1,
"name": "aaaaa",
"attr": [{"attr_code": "a_id", "value": "5"}],
"a_id" : {"id": 5, "name": "bcd"}
},
{
"id": 2,
"name": "bbbbb",
"attr": [{"attr": "a_id", "value": "4"}],
"a_id" : {"id": 4, "name": "bef"}
}]
I am looking to add the array2 objects into array1 based on id's of array2. I have tried using map function on both the arrays to compare and add the object but I didn't succeed. Can you please suggest me how to do it?
Thank you
Add the array2 objects into array1 based on ids of array2.
let array1 =
[
{
"id": 1,
"name": "aaaaa",
"attr": [{"attr_code": "a_id", "value": "5"}]
},
{
"id": 2,
"name": "bbbbb",
"attr": [{"attr": "a_id", "value": "4"}]
}
];
let array2 = [{
"id": 4,
"name": "bef",
},
{
"id": 5,
"name": "bcd",
}
];
let resultingArray=[];
array1.forEach(function(element) {
element['a_id'] = [];
element['attr'].forEach(function(attr) {
element['a_id'].push(array2.find(function(item) {
return item.id == attr.value;
}));
});
resultingArray.push(element)
});
console.log(resultingArray);
I presume you intend to extract the object whose ID is equal to the value field the in the each object in array1.
var array1 = [{
"id": 1,
"name": "aaaaa",
"attr": [{"attr_code": "a_id", "value": "5"}]
},
{
"id": 2,
"name": "bbbbb",
"attr": [{"attr": "a_id", "value": "4"}]
}];
var array2 = [{
"id": 4,
"name": "bef",
},
{
"id": 5,
"name": "bcd",
}];
var resultingArray = [];
for(var i = 0; i < array1.length; i++) {
resultingArray[i] = array1[i];
for(var j = 0; j < array2.length; j++) {
if(resultingArray[i].attr[0].attr_code.value === array2[j].id) {
resultingArray[i].push("a_id": array2[j]);
}
}
}
You just need to lop through array1, and for each object in array1, you need to find corresponding objects in array2 which match the criterion.
You can use array map and array index to do:
var array1 = [{
"id": 1,
"name": "aaaaa",
"attr": [{"attr_code": "a_id", "value": "5"}]
},
{
"id": 2,
"name": "bbbbb",
"attr": [{"attr": "a_id", "value": "4"}]
}];
var array2 = [{
"id": 4,
"name": "bef",
},
{
"id": 5,
"name": "bcd",
}];
var result = array1.map(current=>{
//find index of attr in array2
let index = array2.findIndex(c=>{
if (c['id']===(Number(current['attr'][0]['value'])))
return c;
});
current["a_id"] = array2[index];
return current;
});
console.log(result);
Please check if the following code suites your requirement. You may need to make some changes.
function mergeArrays3 (arr1, arr2) {
return arr1.map((value, index) => {
let object = null;
let result = {...value};
for (let element of arr2) {
if (element.id == parseInt(value.attr[0].value)) {
object = element;
break;
}
}
if (object != null) {
let attr = value.attr[0];
if (attr.hasOwnProperty("attr")) {
result[value.attr[0].attr] = object;
} else if (attr.hasOwnProperty("attr_code")) {
result[value.attr[0].attr_code] = object;
}
}
return result;
});
}
I loop over first array and find an element in second array matching id of value.attr[0].value. If found then i added this object in the first array at key of value.attr[0].attr or value.attr[0].attr_code.
I have tried using map function on both the arrays to compare and add
the object but I didn't succeed
Below is the functional programming approach using map():
/* GIVEN */
const array1 = [{
"id": 1,
"name": "aaaaa",
"attr": [{
"attr_code": "a_id",
"value": "5"
}]
},
{
"id": 2,
"name": "bbbbb",
"attr": [{
"attr": "a_id",
"value": "4"
}]
}
]
const array2 = [{
"id": 4,
"name": "bef",
},
{
"id": 5,
"name": "bcd",
}]
/* From array2, make an object keyed by the 'id' field. We'll use this as a key-value lookup table */
const lookupTable = array2.reduce((accum, item) => {
accum[item.id.toString()] = item
return accum
}, {})
console.log('***LOOKUP TABLE***\n', lookupTable) // result is an object we use to lookup
/* From array1, we append data from the lookup table */
const final = array1.map(item => {
item.a_id = lookupTable[item.attr[0].value]
return item
})
console.log("***RESULT***\n", final)
Hope this helps.
Cheers,
I want to build an new JSON from existing one. The source has sections and rubrics that I no longer need for a listing. The new object called 'items' should have an array of the items.
The final JSON should be sorted by attribute 'name' and look like
{
"items": [
{
"id": 10000006,
"name": "Boah"
},
{
"id": 10000013,
"name": "Gut"
},
{
"id": 10000003,
"name": "Ipsum"
},
{
"id": 10000001,
"name": "Lorem"
},
{
"id": 10000005,
"name": "Lorum"
},
{
"id": 10000004,
"name": "Name"
},
{
"id": 10000002,
"name": "Stet"
}
]
}
For building the new JSON I get this source:
{
"sections": [
{
"name": "FooBar",
"rubrics": [
{
"name": "Foo",
"items": [
{
"id": 10000001,
"name": "Lorem"
},
{
"id": 10000002,
"name": "Stet"
},
{
"id": 10000003,
"name": "Ipsum"
}
]
},
{
"name": "Bar",
"items": [
{
"id": 10000004,
"name": "Name"
},
{
"id": 10000005,
"name": "Lorum"
},
{
"id": 10000006,
"name": "Boah"
}
]
}
]
},
{
"name": "BlahBloob",
"rubrics": [
{
"name": "Bla",
"items": [
{
"id": 10000013,
"name": "Gut"
}
]
},
{
"name": "Bloob",
"items": [
{
"id": 10000014,
"name": "Name"
},
{
"id": 10000015,
"name": "Lorem"
}
]
}
]
}
]
}
What do you think? How can I do this with plain JavaScript or maybe TypeScript?
Thanks for reading and have time for my question. And thanks for reply in advance.
Here you go. You just need to iterate over each rubric of each section of your source to get the items. At the end, sort your list of items by items, and you're done.
This example uses ES6 syntax, but it's easy to convert it to ES5 if needed.
function extractItems(source) {
const items = [];
for (const section of source.sections) {
for (const rubric of section.rubrics) {
items.push(...rubric.items);
}
}
items.sort((a, b) => a.name.localeCompare(b.name));
return { items };
}
A more functional approach use map and reduce to pick the rubrics and merge them.
data.sections
.map(section => section.rubrics) // get rubrics
.reduce((a, b) => a.concat(b)) // merge rubrics
.map(rubric => rubric.items) // get items from each rubric
.reduce((a, b) => a.concat(b)) // merge items
.sort((a, b) => a.name.localeCompare(b.name)); // sort
function(oldObj) {
var newObj = {
"items": []
};
oldObj.sections.forEach(function(section) {
section.rubrics.forEach(function(rubric) {
rubric.items.forEach(function(item) {
newObj.items.push(item);
});
});
});
newObj.items = newObj.items.sort(function(a, b) {
if (a.name < b.name) { return -1; }
if (a.name > b.name) { return 1; }
return 0;
});
return newObj;
}
And simply use JSON.parse() and JSON.stringify() to convert JSON to and from objects.
It might help you
var data ={
"sections": [
{
"name": "FooBar",
"rubrics": [{"name": "Foo", "items": [{"id": 10000001,"name": "Lorem"}, {"id": 10000002,"name": "Stet"}, {"id": 10000003,"name": "Ipsum"}]
}, {
"name": "Bar",
"items": [{
"id": 10000004,
"name": "Name"
}, {
"id": 10000005,
"name": "Lorum"
}, {
"id": 10000006,
"name": "Boah"
}]
}]
}, {
"name": "BlahBloob",
"rubrics": [{
"name": "Bla",
"items": [{
"id": 10000013,
"name": "Gut"
}]
}, {
"name": "Bloob",
"items": [{
"id": 10000014,
"name": "Name"
}, {
"id": 10000015,
"name": "Lorem"
}]
}]
}]
};
var itemObj = {};
var itemArr = [];
var sections = data.sections;
for(var i=0;i<sections.length;i++)
{
for(var j=0;j<sections[i].rubrics.length;j++){
for(var k=0;k<sections[i].rubrics[j].items.length;k++){
var itemObj;
itemObj['id'] = sections[i].rubrics[j].items[k].id;
itemObj['name'] = sections[i].rubrics[j].items[k].name;
itemArr.push(itemObj);
}
}
}
var finalObj = {"items":itemArr};
console.log(finalObj);
JSFiddle
How would I be able to nest json object if the parent and its children was given as a property.
The data looks like:
"1": {
"id": 1,
"name": "foo",
"parent": null,
"root": 1,
"children": [2, 4, 6],
"posts":[
{ "id": "1", "name": "item1" },
{ "id": "2", "name": "item2" },
{ "id": "3", "name": "item3" }
]
},
"2": {
"id": 2,
"name": "bar",
"parent": 1,
"root": 1,
"children": null,
"posts":[
{ "id": "4", "name": "item4" }
]
},
"3": {
"id": 3,
"name": "bazz",
"parent": null,
"root": 3,
"children": [5, 7],
"posts":[
{ "id": "5", "name": "item5" },
{ "id": "6", "name": "item6" }
]
},
....
A simple groupby using lodash won't do it.
var group = _.groupBy(data, 'parent');
Here is a fiddle:
http://jsfiddle.net/tzugzo8a/1/
The context of question is a nested categories with subcategories, and categories can have categories and posts in them.
Basically I don't want to have a different property for children and posts, since they are all children of a parent.
Desired output
"1": {
"id": 1,
"name": "foo",
"parent": null,
"root": 1,
"isCategory": true,
"children": [
{
"id": 2,
"name": "bar",
"parent": 1,
"root": 1,
"isCategory": true,
"children": null
},
{ "id": "1", "name": "item1", isCategory: false },
{ "id": "2", "name": "item2", isCategory: false },
{ "id": "3", "name": "item3", isCategory: false }
]
...
}
This is my take on the question (fiddle):
var data = getData();
var group = getTree(data);
console.log(group);
function getTree(flat) {
return _.reduce(flat, function (treeObj, item, prop, flatTree) {
var children = _.map(item.children, function (childId) {
return _.set(flatTree[childId], 'isCategory', true);
}).concat(_.map(item.items, function(item) {
return _.set(item, 'isCategory', false);
}));
item.children = !!children.length ? children : null;
delete item.items;
item.parent === null && (treeObj[prop] = item);
return treeObj;
}, {});
}
Take a look on the updated fiddle:
var data = getData();
_.keys(data).forEach(function(id){
var element = data[id];
if (element.children === null){
element.children = [];
}
element.isCategory = true;
element.items.forEach(function(item){
item.isCategory = false;
})
});
_.keys(data).forEach(function(id){
var element = data[id];
element.children = element.children.map(function(childId){
return data[childId];
}).concat(element.items);
});
_.keys(data).forEach(function(id){
delete data[id].items;
});
console.log(JSON.stringify(_.findWhere(_.values(data), {'parent': null})));