JSON: How to get data from a same "column" with different names? - javascript

I have my JSON file as follows:
{
"data": {
"member1": {
"id": 1,
"name": "Gather",
"symbol": "AB1"
"last_updated": 1525137271
},
"member2": {
"id": 2,
"name": "Banner",
"symbol": "AB2",
"last_updated": 1525137260
},
"member3": {
"id": 3,
"name": "Tecker",
"symbol": "AB3",
"last_updated": 1525137260
},
"member4": {
"id": 4,
"name": "Walter",
"symbol": "AB4",
"last_updated": 1525137260
}
}
I would like to get the data ONCE from "member1", "member2"...
Of course it would be easy to get the data if the names were all identical. Any ideas ?


You can use Object.keys, Object.values and Object.entries to enumerate the properties of an object.
In your case, for example, let's say we wanted an array of all the names:
Object.values(json.data).map(member => member.name)
Here's a nice article that explains the three.

Related

Filter array of specific objects

How to use filter or forEach in javascript to output only the objects whithout parentId and the objects with only the first level of parentId.
Should output objects with ids: 1681, 1682, and 1683.
Should not output objects with ids: 1685, 1686 and 1687.
array = [ {
"id": 1681,
"label": "1",
"url": "page1",
},
{
"id": 1682,
"label": "2",
"url": "page1",
},
{
"id": 1683,
"label": "a",
"url": "page1",
"parentId": 1681,
},
{
"id": 1685,
"label": "aa",
"url": "page1",
"parentId": 1683,
},
{
"id": 1686,
"label": "aaa",
"url": "page1",
"parentId": 1683,
},
{
"id": 1687,
"label": "aaaa",
"url": "page1",
"parentId": 1683,
}
]
Something like this...
array.filter(({item}) => !item.parentId ? item.id : item.parentId)

We have to save the information if we already found a parentId from inside the filter function. A handy way to do this is by using the prefix operator ++ on a counter. This way we get around an explicit, long assignment with =. Instead we make it before.
Additionally with destructuring assignment we can extract the parentId comfortably of the array items and write a really short filter:
array=[{id:1681,label:"1",url:"page1"},{id:1682,label:"2",url:"page1"},{id:1683,label:"a",url:"page1",parentId:1681},{id:1685,label:"aa",url:"page1",parentId:1683},{id:1686,label:"aaa",url:"page1",parentId:1683},{id:1687,label:"aaaa",url:"page1",parentId:1683}];
window.parentIdCount = 0;
window.filtered =
array.filter(({parentId}) => !parentId || ++parentIdCount <= 1)
console.log(filtered)

Something like this ought to work:
const result = array.filter(object => object.parentId === undefined);

Accessing a specific key in JSON?

I'm trying to access the "title" section (key?) of this JSON object using NodeJS. I can return the entire object, but every time I try to access the key, undefined is returned.
[
[
{
"id": 119,
"title": "Roadhouse",
"url": "https://funsite.com/2021/03/20/funny/",
"date": "2021-03-20"
}
],
[
{
"id": 208,
"title": "New Sites",
"url": "https://coolsitestuff.com/notes/coolsite/",
"date": "2021-03-17"
}
],
[
{
"id": 13,
"title": "woah sites!!",
"url": "https://now.lettuce.com/then/2021-0000/",
"date": "2021-03-07"
}
],
[
{
"id": 120,
"title": "mynewalbumn",
"url": "https://notarealsite.com/2021/03/06/next-album/",
"date": "2021-03-06"
}
],
[
{
"id": 140,
"title": "fightingthemans",
"url": "http://fightcats.com/2021/03/06/keyfights",
"date": "2021-03-06"
}
],
[
{
"id": 14,
"title": "biggest lettuce youll ever see",
"url": "https://morelettuce.com/then/biggestlettuceleaf/",
"date": "2021-02-28"
}
]
]
NodeJS
const fs = require('fs')
fs.readFile('./data/links.json', 'utf8', (err, fsToString) => {
let data = JSON.parse(fsToString);
console.log(data.map(link => link[link.url]))
})
I've tried for loops and indexing that way but I haven't been able to get anything out of it.

You have 2 arrays, either loop over both of them or access it using index
let data =[
[
{
"id": 119,
"title": "Roadhouse",
"url": "https://funsite.com/2021/03/20/funny/",
"date": "2021-03-20"
}
],
[
{
"id": 208,
"title": "New Sites",
"url": "https://coolsitestuff.com/notes/coolsite/",
"date": "2021-03-17"
}
]
]
data.map(link=> console.log(link[0].url))

Your json is array of array objects, you need to access all arrays by index, you can use flatMap and map methods.
var data = [
[{
"id": 119,
"title": "Roadhouse",
"url": "https://funsite.com/2021/03/20/funny/",
"date": "2021-03-20"
}],
[{
"id": 208,
"title": "New Sites",
"url": "https://coolsitestuff.com/notes/coolsite/",
"date": "2021-03-17"
}],
[{
"id": 13,
"title": "woah sites!!",
"url": "https://now.lettuce.com/then/2021-0000/",
"date": "2021-03-07"
}],
[{
"id": 120,
"title": "mynewalbumn",
"url": "https://notarealsite.com/2021/03/06/next-album/",
"date": "2021-03-06"
}],
[{
"id": 140,
"title": "fightingthemans",
"url": "http://fightcats.com/2021/03/06/keyfights",
"date": "2021-03-06"
}],
[{
"id": 14,
"title": "biggest lettuce youll ever see",
"url": "https://morelettuce.com/then/biggestlettuceleaf/",
"date": "2021-02-28"
}]
];
console.log(data.flatMap(i=>i.map(f=>f.url)))

Your current code is trying to access an undefined object property.
Solution:
Replace the link[link.url] for link[0].url. So that the full line is
console.log(data.map(link => link[0].url))
Or if you want the titles:
console.log(data.map(link => link[0].title))

console.log(
data.flat().map(link=>link.url)
);
console.log(
data.map(item=>item[0].url)
);

From what I see your JSON file holds an array of arrays and each nested array contains one object. Therefore data.map(link => link[0].title) should return array of titles

You have an array of arrays and each one with just one position. For the code you posted you're just missing the index of each element.
If you change your code to this you'll get the array with the URL's you're looking for
fs.readFile('./example.json', 'utf8', (err, fsToString) => {
let data = JSON.parse(fsToString);
console.log(data.map(link => link[0].url))
})
Happy coding ;)!

Concatenating child array to parent

Right now I have an array of object with children that also have an array of objects.
[
{
"code": "mock-code",
"name": "mock-name",
"children": [
{
"code": "mock-child-code",
"name": "mock-child-name",
},
{
"code": "mock-child-code",
"name": "mock-child-name",
},
],
},
{
"code": "mock-code",
"name": "mock-name",
"children": [],
},
{
"code": "mock-code",
"name": "mock-name",
"children": [
{
"code": "mock-code",
"name": "mock-name",
}
],
}
]
I want to extract the children array and concat them to the parent array like below.
[
{
"code": "m1",
"name": "mock-name",
"children": [
{
"code": "mc-1",
"name": "mn-1",
},
{
"code": "mc-2",
"name": "mn-2",
},
],
},
{
"code": "m2",
"name": "mock-name",
"children": [],
},
{
"code": "mm3",
"name": "mock-name",
"children": [
{
"code": "mc-3",
"name": "mn-3",
}
],
}
{
"code": "mc-1",
"name": "mn-1",
},
{
"code": "mc-2",
"name": "mn-2",
},
{
"code": "mc-3",
"name": "mn-3",
}
]
What are someways to do this. I'm currently looping though the child array creating a new array checking if it's not empty. It all seems a bit messy. Is there a clean way to do this?
let fullList = New Array()
parentData.forEach(element => {
if (!!element.children.length) {
fullList.push(element.children);
}
});
return parentData.concat(fullList);
This isn't giving me the desired results since it's adding another array to the parent object but this is where I am at.

const newArray = originalArray.flatMap(element => [element, ...element.children])
This should do it, and as a bonus will preserve the order (parent1, parent1's children, parent2, parent2's children etc.)
Of course, this works if you have only one level of nesting. If you have greater depth level, that would be a bit more complex, probably using Array.prototype.reduce().

Using Lodash to transform data into object properties instead of a collection by specifying properties value

following up on my previous question about transforming data using lodash, this time i require output to be an object properties instead of being a collection. I appreciate the help and if someone can also guide me where to begin properly so i have a better understanding of these concepts
Sample Data
{
"changeAccount": {
"add": [
{
"changeType": 1,
"type": "changeAccount",
"updated": {
"id": 71,
"company": 124201,
"user": 8622
}
}
],
"remove": [
{
"changeType": 2,
"type": "changeAccount",
"updated": {
"id": 70,
"company": 124201,
"user": 8622
}
}
]
},
"changeproduct": {
"add": [
{
"changeType": 1,
"type": "changeproduct",
"updated": {
"id": 15,
"company": 124201,
"user": 8622
}
}
],
"remove": []
}
}
Expected Result
var sample = [{
"changeType": 1,
"type": "changeAccount",
"updated": {
"id": 71,
"company": 124201,
"user": 8622
}
},
{
"changeType": 2,
"type": "changeAccount",
"updated": {
"id": 70,
"company": 124201,
"user": 8622
}
},
{
"changeType": 1,
"type": "changeproduct",
"updated": {
"id": 15,
"company": 124201,
"user": 8622
}
}
]

Here is one way to do it:
chain(data)
.values()
.map(_.values)
.flatMapDeep()
.value()
So what's happening here is:
Start with our data which is an object
Use .values to return only the values of our top level properties (i.e. strip away changeProduct and changeAccount
Map the resulting items in the array to only the values of our objects (i.e. strip away add and remove) using .values again
Flatten the entire array recursively so we end up with an array that is one level deep using .flatMapDeep
You might also notice the chain(data) syntax, this is just a way to improve the readability and sometimes performance of your lodash code, so that you don't have to nest each lodash function that you use. Check out the docs on chain for more info.

accessing a json child object not in an array

I'm trying to accessing a json child object which is not in an array. i've tried accessing it with my below script but its not working. i want to be able to access the menuCategory Object
JSON
[
{
"id": 67,
"name": "Wednesday Menu",
"serveDate": "2019-06-12 00:00:00",
"expiryDate": "2019-06-12 16:11:00",
"status": "APPROVED",
"isEnabled": true,
"meals": [
{
"id": 45,
"name": "Waakye, Gari and Wele",
"description": "A very well designed food for all kids",
"image": "",
"mealType": "LUNCH",
"unitPrice": 30,
"status": "ENABLED"
},
{
"id": 46,
"name": "Gari and Beans",
"description": "A very well designed food for all kidsss",
"image": "",
"mealType": "LUNCH",
"unitPrice": 12,
"status": "ENABLED"
}
],
"menuCategory": {
"id": 2,
"name": "hello"
}
}
]
JAVASCRIPT
callEditMenu(parent, content) {
this.modalService.open(content);
this.editMenuCategoryId = parent.menuCategory.id;
}

May be like
const parent = [{"id":67,"name":"Wednesday Menu","serveDate":"2019-06-12 00:00:00","expiryDate":"2019-06-12 16:11:00","status":"APPROVED","isEnabled":true,"meals":[{"id":45,"name":"Waakye, Gari and Wele","description":"A very well designed food for all kids","image":"","mealType":"LUNCH","unitPrice":30,"status":"ENABLED"},{"id":46,"name":"Gari and Beans","description":"A very well designed food for all kidsss","image":"","mealType":"LUNCH","unitPrice":12,"status":"ENABLED"}],"menuCategory":{"id":2,"name":"hello"}}]
console.log(parent[0].menuCategory.id);

If the parent argument in the callEditMenu function is referring to the JSON you included then try parent[0].menuCategory.id

let arr = [{"id":67,"name":"Wednesday Menu","serveDate":"2019-06-12 00:00:00","expiryDate":"2019-06-12 16:11:00","status":"APPROVED","isEnabled":true,"meals":[{"id":45,"name":"Waakye, Gari and Wele","description":"A very well designed food for all kids","image":"","mealType":"LUNCH","unitPrice":30,"status":"ENABLED"},{"id":46,"name":"Gari and Beans","description":"A very well designed food for all kidsss","image":"","mealType":"LUNCH","unitPrice":12,"status":"ENABLED"}],"menuCategory":{"id":2,"name":"hello"}}]
for (let item of arr) {
if (item.hasOwnProperty("menuCategory")) {
console.log(item["menuCategory"]);
}
};
let res = arr.filter((item) => item && item.menuCategory);
console.log(res[0].menuCategory);
In case you need to find it dynamically. Above are two different ways

Considering there would be multiple items in your array of objects, you can iterate through each object to get the menuCategory name as
let obj = [
{
"id": 67,
"name": "Wednesday Menu",
"serveDate": "2019-06-12 00:00:00",
"expiryDate": "2019-06-12 16:11:00",
"status": "APPROVED",
"isEnabled": true,
"meals": [
{
"id": 45,
"name": "Waakye, Gari and Wele",
"description": "A very well designed food for all kids",
"image": "",
"mealType": "LUNCH",
"unitPrice": 30,
"status": "ENABLED"
},
{
"id": 46,
"name": "Gari and Beans",
"description": "A very well designed food for all kidsss",
"image": "",
"mealType": "LUNCH",
"unitPrice": 12,
"status": "ENABLED"
}
],
"menuCategory": {
"id": 2,
"name": "hello"
}
}
];
obj.forEach(elem => {
console.log(elem.menuCategory.name);
});

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