Please guide me with the right way to get this:
Supose i have this data:
var personnel = [
{
id: 5,
name: "Luke Skywalker",
pilotingScore: 98,
shootingScore: 56,
isForceUser: true,
},
{
id: 82,
name: "Sabine Wren",
pilotingScore: 73,
shootingScore: 99,
isForceUser: false,
},
{
id: 22,
name: "Zeb Orellios",
pilotingScore: 20,
shootingScore: 59,
isForceUser: false,
}
];
and i need the result as this:
{ 5: "Luke Skywalker", 82:"Sabine Wren", 22: "Zeb Orellios"}
i have tried with map i also tried foreach, i can not get some approach.
thankyou
I'd use reduce
personnel.reduce((acc, i) => Object.assign(acc, {[i.id]: i.name}), {})
Try this:
var res = {};
for (p of personnel) {
res[p.id] = p.name;
}
Use Array.map() to create an array of [id, name] pairs, and convert to an object using Object.fromEntries():
const personnel = [{"id":5,"name":"Luke Skywalker","pilotingScore":98,"shootingScore":56,"isForceUser":true},{"id":82,"name":"Sabine Wren","pilotingScore":73,"shootingScore":99,"isForceUser":false},{"id":22,"name":"Zeb Orellios","pilotingScore":20,"shootingScore":59,"isForceUser":false}];
const result = Object.fromEntries(personnel.map(o => [o.id, o.name]));
console.log(result);
Related
I'm trying to filter the array by the numbers. Basically, car with id 48 should be deleted because it does not exist on numbers
What am I missing here??
const numbers = [49, 482, 49, 49, 49, 1135, 49, 1709, 1044, 1016, 30];
const array = [{
cars: [{
id: 48
}, {
id: 49
}]
}];
array.forEach(elem => elem.cars.filter(car => !numbers.includes(car.id)));
console.log(array);
I want to keep the same structure, I just want tot delete the car with id 48
You can use a nested forEach
const numbers = [49, 482, 49, 49, 49, 1135, 49, 1709, 1044, 1016, 30];
const array = [{
cars: [{
id: 48
}, {
id: 49
}]
}];
array.forEach(elm => {
const cars = [];
elm.cars.forEach(car => {
if(numbers.includes(car.id)) {
cars.push({id: car.id});
}
});
elm.cars = cars;
});
console.log(array);
Or a reduce within forEach
const numbers = [49, 482, 49, 49, 49, 1135, 49, 1709, 1044, 1016, 30];
const array = [{
cars: [{
id: 48
}, {
id: 49
}]
}];
array.forEach(elm => {
elm.cars = elm.cars.reduce((acc, curr) => {
if (numbers.includes(curr.id)) {
acc.push({
id: curr.id
});
}
return acc;
}, []);
});
console.log(array);
You could use Array.reduce() to acheive the expected result.
The idea is to change the filter condition which allows to keep the car objects id found in the numbers array and eliminate rest.
In your approach Array.forEach is just iteration without returning anything and Array.filter does not mutate the actual array.
const numbers = [49, 482, 49, 49, 49, 1135, 49, 1709, 1044, 1016, 30];
const array = [
{
cars: [
{
id: 48,
},
{
id: 49,
},
],
},
];
const res = array.reduce((prev, curr) => {
prev.push({ cars: curr.cars.filter((car) => numbers.includes(car.id)) });
return prev;
}, []);
console.info("result::", res);
const numbers = [49, 482, 49, 49, 49, 1135, 49, 1709, 1044, 1016, 30];
const array = [
{
cars: [{id: 48,},{id: 49,}],
},
];
array.forEach((elem) => {
const elemCopy = elem;
elemCopy.cars = elem.cars.filter((car) => numbers.includes(car.id))
});
console.log(array);
Please refer the code, while iterating over array we can mutate the cars array.
I've got some headers and peopleData:
const headers = ["name", "age", "nationality"]
const peopleData = [
["John", 31, "Spanish"],
["Jane", 41, "Italian"],
["Johnson", 11, "Thai"],
["Rob", 13, "Japanese"],
]
I want to combine both and return an array of objects looking like:
[{
name: "John",
age: 31,
nationality: "Spanish"
}, {
name: "Jane",
age: 41,
nationality: "Italian"
}, {
name: "Johnson",
age: 11,
nationalityL: "Thai"
}, {
name: "Rob",
age: 13,
nationality: "Japanese"
}]
So far I came up to this:
const people = peopleData.map((person, i) => {
return headers.map((header, index) => {
return {
[header]: person[index]
}
})
})
This solution does not work since it creates nested objects:
[[{
name: "John"
}, {
age: 31
}, {
nationality: "Spanish"
}], [{
name: "Jane"
}, {
age: 41
}, {
nationality: "Italian"
}], [{
name: "Johnson"
}, {
age: 11
}, {
nationality: "Thai"
}], [{
name: "Rob"
}, {
age: 13
}, {
nationality: "Japanese"
}]]
Example below:
Credit to Andreas comment, better performant below
const headers = ["name", "age", "nationality"];
const peopleData = [
["John", 31, "Spanish"],
["Jane", 41, "Italian"],
["Johnson", 11, "Thai"],
["Rob", 13, "Japanese"],
];
const o = peopleData.map(a =>
a.reduce((acc, b, i) => {
acc[headers[i]] = b;
return acc;
}, {})
);
console.log(o);
In one line-er, but less performent
const headers = ["name", "age", "nationality"];
const peopleData = [
["John", 31, "Spanish"],
["Jane", 41, "Italian"],
["Johnson", 11, "Thai"],
["Rob", 13, "Japanese"],
];
const o = peopleData.map(a =>
a.reduce((acc, b, i) => ({ ...acc, [headers[i]]: b }), {})
);
console.log(o);
You can wrap your inner .map() in a call to Object.fromEntries() which will build an object for you - it takes an array of [[key, value],...] pairs, and so you can change your inner map to return a [key, value] pair array instead of objects like so:
const headers = ["name", "age", "nationality"];
const peopleData = [ ["John", 31, "Spanish"], ["Jane", 41, "Italian"], ["Johnson", 11, "Thai"], ["Rob", 13, "Japanese"], ];
const res = peopleData.map(person => Object.fromEntries(person.map(
(val, i) => [headers[i], val]
)));
console.log(res);
Or, you can stick with your approach of returning an array of objects, but then merge the objects within the array together using Object.assign() and the spread syntax ...:
const headers = ["name", "age", "nationality"];
const peopleData = [ ["John", 31, "Spanish"], ["Jane", 41, "Italian"], ["Johnson", 11, "Thai"], ["Rob", 13, "Japanese"], ];
const res = peopleData.map(person => Object.assign(...person.map(
(val, i) => ({[headers[i]]: val})
)));
console.log(res);
A simply solution easy to understand! Iterate all peopleData and put them in a new object using the array headers:
const headers = ["name", "age", "nationality"];
const peopleData = [["John", 31, "Spanish"],["Jane", 41, "Italian"],["Johnson", 11, "Thai"],["Rob", 13, "Japanese"]];
let result = [];
peopleData.forEach((e, i) => { //iterate data
result[i] = {};
result[i][headers[0]] = e[0];
result[i][headers[1]] = e[1];
result[i][headers[2]] = e[2];
});
console.log(result);
I have this object
{TDD_rating: 80, Fluency_rating: 70, Debug_rating: 64, Model_rating: 53, Refactor_rating: 68,}
which I want in the format of this array
[
{ subject: 'TDD', score: 80 },
{ subject: 'Fluency', score: 70},
{ subject: 'Debug', score: 65},
{ subject: 'Model', score: 53},
{ subject: 'Refactor', score: 68},
];
I have tried to use Object.entries and map but can't seem to get there
You could use combination of Object.entries() and Array.prototype.map() method to get your result. Get the key value pairs using Object.entries() method and then map it to make your required object array.
const data = {
TDD_rating: 80,
Fluency_rating: 70,
Debug_rating: 64,
Model_rating: 53,
Refactor_rating: 68,
};
const ret = Object.entries(data).map(([x, y]) => ({
subject: x.replace('_rating', ''),
score: y,
}));
console.log(ret);
You can use Object.keys and map method to achieve that,
const obj = {
TDD_rating: 80,
Fluency_rating: 70,
Debug_rating: 65,
Model_rating: 53,
Refactor_rating: 68,
};
const result = Object.keys(obj).map((key) => ({ subject: key, score: obj[key] }));
console.log(result);
I have the following JavaScript object. I need to generate a new array of objects from the given object. What is the approach I should take in JavaScript?
const ObjOfObj = {
'virus': [
{
'2016': 67,
'2017': 59,
'2018': 18,
'2019': 1
}
],
'cure': [
{
'2016': 51,
'2017': 50,
'2018': 16,
'2019': 1
}
]
};
How can I transform or pivot to generate the following array of objects?
const ArrOfObj = [
{'year': '2016', 'virus': 67, 'cure' : 51},
{'year': '2017', 'virus': 59, 'cure' : 50},
{'year': '2018', 'virus': 18, 'cure' : 16},
{'year': '2019', 'virus': 1, 'cure' : 1},
]
you can use a reduce function like this.
const ObjOfObj = {
'virus': [
{
'2016': 67,
'2017': 59,
'2018': 18,
'2019': 1
}
],
'cure': [
{
'2016': 51,
'2017': 50,
'2018': 16,
'2019': 1
}
]
};
const groupBy = (obj) => {
const keys = Object.keys(obj);
const mapping = keys.reduce((acc, k) => {
obj[k].forEach(item => {
Object.keys(item).forEach(yearKey => {
tracked = acc[yearKey];
if (!tracked) {
acc[yearKey] = {
year: yearKey
};
}
acc[yearKey][k] = (acc[yearKey][k] | 0) + item[yearKey];
});
});
return acc;
}, {});
return Object.entries(mapping);
};
console.log(groupBy(ObjOfObj));
I am trying to handle JSON arrays to extract key value pair from the keys available from user selection.
This is not real time json example...It is just a sample
Example of JSON
var personnel = [
{
id: 5,
name: "Luke Skywalker",
pilotingScore: 98,
shootingScore: 56,
isForceUser: true,
},
{
id: 82,
name: "Sabine Wren",
pilotingScore: 73,
shootingScore: 99,
isForceUser: false,
skills:{
'skill1':'vision',
'skill2':'strength'
}
},
{
id: 22,
name: "Zeb Orellios",
pilotingScore: 20,
shootingScore: 59,
isForceUser: false,
},
{
id: 15,
name: "Ezra Bridger",
pilotingScore: 43,
shootingScore: 67,
isForceUser: true,
skills:{
'skill1':'vision',
'skill2':'strength'
}
},
{
id: 11,
name: "Caleb Dume",
pilotingScore: 71,
shootingScore: 85,
isForceUser: true,
},
];
sample_arr = [id,name,skills.skill1];
let op = personnel.map(md => {
return { id: md.id,name:md.name,skills{skill1:md.skills.skill1}};
});
console.log(JSON.stringify(op,null,2))
I wanted to get key value pair like below.
[
{
"id": 5,
"name": "Luke Skywalker"
},
{
"id": 82,
"name": "Sabine Wren",
"skills":{
"skill1": 'vision'
}
},
{
"id": 22,
"name": "Zeb Orellios"
},
{
"id": 15,
"name": "Ezra Bridger"
},
{
"id": 11,
"name": "Caleb Dume"
}
]
I now updated the my problem statement.
Requirement:
Extract all JSON values selected by the user to a new array. This will save more time as the json is 700MB all the way and it is time consuming to handle on every request
You have the user selections stored in the array? If so, you could do something like:
let sample_arr = ['id', 'name']
let op = personnel.map(md => {
let user = {}
sample_arr.forEach(val => {
if (md[val]) {
user[val] = md[val]
}
})
return user
})
Here's a simple function to do this:
const project = (keys) => (xs) =>
xs .map (x => keys .reduce ( (a, k) => ({...a, [k]: x[k]}), {} ))
var personnel = [{id:5,name:"Luke Skywalker",pilotingScore:98,shootingScore:56,isForceUser:true},{id:82,name:"Sabine Wren",pilotingScore:73,shootingScore:99,isForceUser:false,skills:{skill1:"vision",skill2:"strength"}},{id:22,name:"Zeb Orellios",pilotingScore:20,shootingScore:59,isForceUser:false},{id:15,name:"Ezra Bridger",pilotingScore:43,shootingScore:67,isForceUser:true,skills:{skill1:"vision",skill2:"strength"}},{id:11,name:"Caleb Dume",pilotingScore:71,shootingScore:85,isForceUser:true}];
console .log (
project (['id', 'name']) (personnel)
)
The name project is from Codd's early papers on relational databases; it's similar in feel to SQL's select statement.
Update
The answer from KellyKapoor has one feature the above lacks: it only includes the property name if the data has it (so no skills: undefined.)
It's not clear which behavior the OP is looking for, but this minor modification offers that feature
const project2 = (keys) => (xs) =>
xs .map (x => keys .reduce ((a, k) => ({...a, ...(k in x ? {[k]: x[k]} : {}) }), {} ))
var personnel = [{id:5,name:"Luke Skywalker",pilotingScore:98,shootingScore:56,isForceUser:true},{id:82,name:"Sabine Wren",pilotingScore:73,shootingScore:99,isForceUser:false,skills:{skill1:"vision",skill2:"strength"}},{id:22,name:"Zeb Orellios",pilotingScore:20,shootingScore:59,isForceUser:false},{id:15,name:"Ezra Bridger",pilotingScore:43,shootingScore:67,isForceUser:true,skills:{skill1:"vision",skill2:"strength"}},{id:11,name:"Caleb Dume",pilotingScore:71,shootingScore:85,isForceUser:true}];
console .log (
project2 (['id', 'name', 'skills']) (personnel)
)
Whats the problem with this?
let op = personnel.map(md => {
return { id: md.id,name:md.name};
});
You can create a function which extracts the props from an object based on a passed array of keys:
var data = [ { id: 5, name: "Luke Skywalker", pilotingScore: 98, shootingScore: 56, isForceUser: true, }, { id: 82, name: "Sabine Wren", pilotingScore: 73, shootingScore: 99, isForceUser: false, skills:{ 'skill1':'vision', 'skill2':'strength' } }, { id: 22, name: "Zeb Orellios", pilotingScore: 20, shootingScore: 59, isForceUser: false, }, { id: 15, name: "Ezra Bridger", pilotingScore: 43, shootingScore: 67, isForceUser: true, skills:{ 'skill1':'vision', 'skill2':'strength' } }, { id: 11, name: "Caleb Dume", pilotingScore: 71, shootingScore: 85, isForceUser: true, }, ];
let pick = (obj, fields) => Object.keys(obj)
.reduce((r,c) => (fields.includes(c) ? r[c] = obj[c] : null, r), {})
let result = data.map(x => pick(x, ['id', 'name', 'skills']))
console.log(result)
Then all you need is to loop though via Array.map to pick from all objects.