Reducing values array of objects to an array without duplicates using Set - javascript

I have following array of object:
[{
"user": {
"tags": [{
"tag": "T1"
},{
"tag": "T2"
}]
}
},
{
"user": {
"tags": [{
"tag": "T2"
}]
}
}, {
"user": {
"tags": [{
"tag": "T3"
}]
}
}]
And need to collect all the tags with no duplicates as below using ES6 Set
["T1","T2","T3"]
Can any one help me?

I agree with the comments. Here's a nested loop implementation,
const data = [{
"user": {
"tags": [{
"tag": "T1"
},{
"tag": "T2"
}]
}
},
{
"user": {
"tags": [{
"tag": "T2"
}]
}
}, {
"user": {
"tags": [{
"tag": "T3"
}]
}
}];
const tagsSet = new Set([]);
data.forEach(val => {
val.user.tags.forEach(t => {
if(!tagsSet.has(t.tag)){
tagsSet.add(t.tag);
}
});
});
console.log(tagsSet); // Set(3) {"T1", "T2", "T3"}

Got the answer using reduce and Set. Thanks T.J.Crowder !
const data = [{
"user": {
"tags": [{
"tag": "T1"
},{
"tag": "T2"
}]
}
},
{
"user": {
"tags": [{
"tag": "T2"
}]
}
}, {
"user": {
"tags": [{
"tag": "T3"
}]
}
}];
let uniqueTags = []
const allTags = data.reduce((current , next) => {
current.user.tags.push(...next.user.tags);
return current;
});
uniqueTags = [... new Set(allTags.user.tags.map(t => t.tag))];
console.log(uniqueTags);

Related

nest items in JSON based on value?

Trying to get my head around this one..
Incoming data looks like:
[
{
"value": {
"label": "MZ Algal bloom",
"type": "case",
"incident": {
"name": "Algal bloom"
},
"personName": "Lionel Carter"
}
},
{
"value": {
"label": "BW Algal bloom",
"type": "case",
"incident": {
"name": "Algal bloom"
},
"personName": "Jerome Yost"
}
},
{
"value": {
"label": "Detergent",
"type": "case",
"incident": null,
"personName": "Jerald Legros"
}
}
]
I would like to transform this into
[
{
"label": "Algal bloom",
"children": [
{ "label": "Lionel Carter", "type": "case"},
{ "label": "Jerome Yost", "type": "case" }]
},
{ "label": "Detergent", "type": "case" }
]
Basically, the rule is that if incident is not NULL then the incident name becomes the parent and the children hold the personName - otherwise we simply pass through the label and type. I can walk the array and switch out the label with the incident name, but I'm not sure how to group up the incidents..
It's basic grouping with an exception for elements without incident.
You can group the elements without incident in a separate group:
const data = [{"value": {"label": "MZ Algal bloom","type": "case","incident": {"name": "Algal bloom"},"personName": "Lionel Carter"}},{"value": {"label": "BW Algal bloom","type": "case","incident": {"name": "Algal bloom"},"personName": "Jerome Yost"}},{"value": {"label": "Detergent","type": "case","incident": null,"personName": "Jerald Legros"}}];
function group(data) {
const result = data.reduce((acc, { value }) => {
if (!value.incident) {
acc.ungrouped.push({ label: value.label, type: value.type });
} else {
if (!acc.groups[value.incident.name]) acc.groups[value.incident.name] = { label: value.incident.name, children: [] };
acc.groups[value.incident.name].children.push({ label: value.personName, type: value.type });
}
return acc;
}, { groups: {}, ungrouped: [] });
return [...Object.values(result.groups), ...result.ungrouped];
}
console.log(group(data));

javascript print nested array to screen

I have a data array, there are multiple objects in this array, and the data object is an array. There may be more than one object in this array. How can I copy these objects under a single array?
const test = []
const data = [
{
"_id": "124141",
"name": "test",
"data": [
{
"price":10,
"title": "sda"
},
]
},
{
"_id": "2525",
"name": "test2",
"data": [
{
"price":20,
"title": "asdas"
},
]
}
]
[{
"price":10,
"title": "sda"
},
{
"price":20,
"title": "asdas"
},
]
If this is the output I expect, it should be like this. how can I do that
const data = [
{
"_id": "124141",
"name": "test",
"data": [
{
"price":10,
"title": "sda"
},
{
"price":99,
"title":"aaaaa"
}
]
},
{
"_id": "2525",
"name": "test2",
"data": [
{
"price":20,
"title": "asdas"
},
]
}
];
console.log(data.map(e => e.data).flat());
// OR
console.log(data.flatMap(e => e.data));

Create a nested json object from another nested json object [HOLD]

As the question states, I want to create a new object from a current json object.
My current json object:
{
"name": "Parent",
"children": [
{
"name": "Child1",
"children": [
{
"name": "GrandChid1",
"children": []
},
{
"name": "GrandChild2",
"children": []
},
{
"name": "GrandChild3",
"children": [
{
"name": "GrandGrandChild1",
"children": [
{
"name": "GrandGrandGrandChild1",
"children": []
},
{
"name": "GrandGrandGrandChild2",
"children": []
}
]
}
]
}
]
}
]
}
Now the new object will look something like this:
{
"Parent": [
{
"Child1": [
{
"GrandChid1": ''
},
{
"GrandChild2": ''
},
{
"GrandChild3": [
{
"GrandGrandChild1": [
{
"GrandGrandGrandChild1": ''
},
{
"GrandGrandGrandChild2": ''
}
]
}
]
}
]
}
]
}
If there are no children then it becomes a string (simple key value) pair.
Any help is appreciated especially with a recursive solution.
Try
let r = o=> (o.children=o.children.map(x=>r(x)),
{[o.name]: o.children.length ? o.children:''});
let c= {
"name": "Parent",
"children": [
{
"name": "Child1",
"children": [
{
"name": "GrandChid1",
"children": []
},
{
"name": "GrandChild2",
"children": []
},
{
"name": "GrandChild3",
"children": [
{
"name": "GrandGrandChild1",
"children": [
{
"name": "GrandGrandGrandChild1",
"children": []
},
{
"name": "GrandGrandGrandChild2",
"children": []
}
]
}
]
}
]
}
]
}
let r = o=> (o.children=o.children.map(x=>r(x)),{[o.name]: o.children.length ? o.children:''});
console.log(r(c));

JS How to remove an object from array in a forEach loop?

I have a data object with following contents:
{
"content": {
"id": "someID",
"type": "unit",
"method": "xyz",
"blocks": [{
"key": "blue",
"data": [
"Array"
]
}, {
"key": "red",
"data": [
"Array"
]
}, {
"key": "yellow",
"data": [
"Array"
]
}, {
"key": "black",
"data": [
"Array"
]
}],
"notes": "abc"
}
}
I want to remove block that has key yellow, by looping over blocks, rest of the data should be preserved as is. So expected end result would be
{
"content": {
"id": "someID",
"type": "unit",
"method": "xyz",
"blocks": [{
"key": "blue",
"data": [
"Array"
]
}, {
"key": "red",
"data": [
"Array"
]
}, {
"key": "black",
"data": [
"Array"
]
}],
"notes": "abc"
}
}
Data is dynamic so I dont know what would be returned, it might have a match for my condition or it might not.
I've tried a bunch of approaches but nothing seems to have worked so far. I can use lodash too if its any easier. None of those seems to be working. Any help/direction is appreciated
1. Using **delete**
const deleteUnwantedBlock = contentObj => {
const updatedData = contentObj;
const blocks = _.get(updatedData, 'blocks', []);
blocks.forEach(block => {
if (block.key.includes('yellow')) {
delete updatedData.block;
}
});
return updatedData;
};
console.log(deleteUnwantedBlock(data.content));```
2. Using rest operator:
const deleteUnwantedBlock = contentObj => {
const blocks = _.get(contentObj, 'blocks', []);
blocks.forEach(block => {
if (block.key.includes('yellow')) {
let { block, ...restOfTheData } = updatedData;
}
return { ...updatedEntry };
});
};
console.log(deleteUnwantedBlock(data.content));
You just need to filter:
const obj = {
"content": {
"id": "someID",
"type": "unit",
"method": "xyz",
"blocks": [{
"key": "blue",
"data": [
"Array"
]
}, {
"key": "red",
"data": [
"Array"
]
}, {
"key": "yellow",
"data": [
"Array"
]
}, {
"key": "black",
"data": [
"Array"
]
}],
"notes": "abc"
}
};
obj.content.blocks = obj.content.blocks.filter(({ key }) => key !== 'yellow');
console.log(obj);

Building new JSON from existing one

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

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