create new array from nested array object - javascript

i want to create a new array from api, but i don't know how to make it, i'm very confused in looping each array
This is each data
const group_one = [
{
name: "smash",
id: "012112"
},
{
name: "ahlan wa sahlan",
id: "123123"
},
{
name: "ahh",
id: "1231239"
},
{
name: "laki",
id: "21312"
}
];
const group_two = [
{
name: "ahh",
id: "1231239"
},
{
name: "laki",
id: "21312"
}
];
const group_three = [
{
name: "smash",
id: "012112"
},
{
name: "ahlan wa sahlan",
id: "123123"
}
];
this is the main data of api
const data = [
{
body: group_one,
group_id: "01"
},
{
body: grouop_two,
group_id: "02"
},
{
body: group_three,
group_id: "03"
}
];
export default data;
i want to create a new array like this, bcs i want to create a new object containing the group_id of each same data in the array
const newArray = [
{
name: "smash",
id: "012112",
group_id: ["01","03"]
},
{
name: "ahlan wa sahlan",
id: "123123",
group_id: ["01","03"]
},
{
name: "ahh",
id: "1231239",
group_id: ["01","02"]
},
{
name: "laki",
id: "21312",
group_id: ["01","02"]
}
];
can someone help me? with articles or codes.
thanks for helping me (sry for my bad english)

Please see below commented code:
const group01 = [
{
name: 'smash',
id: '012112'
},
{
name: 'ahlan wa sahlan',
id: '123123'
},
{
name: 'ahh',
id: '1231239'
},
{
name: 'laki',
id: '21312'
}
];
const group02 = [
{
name: 'ahh',
id: '1231239'
},
{
name: 'laki',
id: '21312'
}
];
const group03 = [
{
name: 'smash',
id: '012112'
},
{
name: 'ahlan wa sahlan',
id: '123123'
}
];
const data = [
{
body: group01,
group_id: '01'
},
{
body: group02,
group_id: '02'
},
{
body: group03,
group_id: '03'
}
];
function regroup(input) {
// USE Map FOR EASIER ITEM HANDLING.
const output = new Map();
// LOOP MAIN DATA ARRAY.
input.forEach(({body, group_id}) => {
// LOOP EACH GROUP.
body.forEach(({name, id}) => {
// USE id TO GET AN ITEM FROM output OR CREATE A NEW ONE IF IT DOES NOT EXIST.
const item = output.get(id) || {name, id, group_id: []};
// PUSH CURRENT group_id TO THE RESPECTIVE ARRAY.
item.group_id.push(group_id);
// SAVE ITEM TO OUTPUT Map AGAIN.
output.set(id, item);
});
});
// RETURN OUTPUT.
return Array.from(output.values());
}
const new_data = regroup(data);
console.log(new_data);

Related

Filter data from Array of Objects contains Array of Objects

Here I have attendance details and I Want to filter every data that contains employees id:1.
for example: I have data like this:
const attendance = [
{
date: 1,
employees: [
{
id: 1,
name: 'mahadev',
status: 'p'
},
{
id: 2,
name: 'roshan',
status: 'p'
},
]
},
{
date: 2,
employees: [
{
id: 1,
name: 'mahadev',
status: 'a'
},
{
id: 2,
name: 'roshan',
status: 'p'
},
]
},
];
And I want Output like this:
[
{
date:1,
employees: [
{
id:1,
name:'mahadev',
status:'p'
}
]
},
{
date:2,
employees: [
{
id:1,
name:'mahadev',
status:'a'
}
]
},
]
Try using map and filter.
const attendance = [{
date: 1,
employees: [
{ id: 1, name: 'mahadev', status: 'p' },
{ id: 2, name: 'roshan', status: 'p' }
]
},
{
date: 2,
employees: [
{ id: 1, name: 'mahadev', status: 'a' },
{ id: 2, name: 'roshan', status: 'p' }
]
},
];
const filtered = id =>
attendance.map(a => {
const employees = a.employees.filter(e => e.id === id);
return { ...a, employees };
});
console.log(filtered(1));
Using map() and filter()
const filtered = id =>
attendance.map(a => {
const employees = a.employees.filter(emp => emp.id === id);
return { date:a.date, employees };
});
console.log(filtered(1))

How to remove underscore from loop items?

I am trying to remove all the _er and _bx from the array, how can I do it? The way I tried doesn't seem to work. I'd like to see a solution where it removes all after _, and aswell only the letter that I put in for e.g remove all _ with er after.
const nullValue = {
collection: [{
name: "test_er"
},
{
name: "test_bx"
},
{
name: "fred"
},
{
name: "test_er"
}
]
};
const newArr = []
for (let [key, item] of nullValue.collection.entries()) {
item.name.replace(/_er/g, '')
newArr.push(item)
}
console.log(newArr)
Is this what you're looking for?
const nullValue = {
collection: [
{
name: 'test_er',
},
{
name: 'test_bx',
},
{
name: 'fred',
},
{
name: 'test_er',
},
],
};
nullValue.collection = [
...nullValue.collection.map(item => ({
name: item.name.replace(/_.*$/, ''),
})),
];
console.log(nullValue);
You can also use .split('_')[0] with the map method similar to Dmitry's answer... This gives you the first string of the split array, split at the underscore...
const nullValue = {
collection: [{
name: "test_er"
},
{
name: "test_bx"
},
{
name: "fred"
},
{
name: "test_er"
}
]
};
nullValue.collection = [ ...nullValue.collection.map( names => ({ name: names.name.split('_')[0], })),]
console.log(nullValue)
If you want to keep the original array of objects...
const nullValue = {
collection: [{
name: "test_er"
},
{
name: "test_bx"
},
{
name: "fred"
},
{
name: "test_er"
}
]
};
const newArr = { collection :
[ ...nullValue.collection.map( names =>
({ name: names.name.split('_')[0], })),
]}
console.log('newArr = ', newArr)
console.log('nullValue = ', nullValue)
You were VERY close with your original code, but the mistake was that String.replace() does not operate in-place, but rather returns its result. I've modified your code and added a comment below:
const nullValue = {
collection: [{
name: "test_er"
},
{
name: "test_bx"
},
{
name: "fred"
},
{
name: "test_er"
}
]
};
const newArr = []
for (let [key, item] of nullValue.collection.entries()) {
// My change is here
newArr.push( item.name.replace(/_er/g, '') )
}
console.log(newArr)
const nullValue = {
collection: [
{
name: "test_er"
},
{
name: "test_bx"
},
{
name: "fred"
},
{
name: "test_er"
}
]
};
nullValue.collection = nullValue.collection.map(i => i.name.replace(/_.*$/, ''))
console.log(nullValue)
This is preferable to .map() since you don't need a new array. You just want to change the strings:
const nullValue = {
collection: [
{ name: "test_er" },
{ name: "test_bx" },
{ name: "fred" },
{ name: "test_er" }
]
};
nullValue.collection.forEach(i => i.name = i.name.replace(/_.*$/, ''));
console.log(nullValue.collection);

How to group object inside array

Here is what I have
[
{
typeProgramId: {
name: 'type1',
},
title: 'test1',
},
{
typeProgramId: {
name: 'type1',
},
subTypeProgramId: [{
name: 'sub1',
}],
title: 'test2',
},
{
typeProgramId: {
name: 'type2',
},
title: 'test3',
},
{
typeProgramId: {
name: 'type2',
},
subTypeProgramId: {
name: 'sub2',
},
title: 'test4',
}
]
First I want to group typeProgramId if the title have the same typeProgramId I want to push title into array by each typeProgramId but If the data have typeProgramId and subTypeProgram Id I want to group subtypeProgramId in typeProgramId too. if not empty subtypeProgramId I want to push it in array title inside subtypeProgram Id. I try to use lodash groupBy and many way but it still did not work.
Here is what I want
{
typeProgramId: [{
name: 'type1',
title: [
'test1',
],
subTypeProgramId: {
name: sub1,
title: [
'test2'
]
}
}, {
name: 'type2',
title: [
'test3',
],
subTypeProgramId: [{
name: sub1,
title: [
'test4'
]
}
}]
}
what I do now
let result = _.groupBy(getProgram, function(data) {
return data.typeProgramId
})
result = _.map(result, function(group, data) {
// I think in here I must groupBy subTypeProgramId again
// the data return all string not object after group
return {
typeProgramId: data,
titile: group,
}
})
Please check the below code. I have used reduce function of Array. It produces the expected result.
function updateMem(mem, prgIndex, val){
if(prgIndex < 0) {
mem.typeProgramId.push({});
prgIndex = mem.typeProgramId.length - 1;
}
mem.typeProgramId[prgIndex].name = val.typeProgramId.name;
if(val.subTypeProgramId){
mem.typeProgramId[prgIndex].subTypeProgramId = Object.assign({}, mem.typeProgramId[prgIndex].subTypeProgramId || {}, {"name" : val.subTypeProgramId.name, "title": []});
mem.typeProgramId[prgIndex].subTypeProgramId.title.push(val.title);
} else {
mem.typeProgramId[prgIndex].title = (mem.typeProgramId[prgIndex].title ? mem.typeProgramId[prgIndex].title : []);
mem.typeProgramId[prgIndex].title.push(val.title);
}
};
arr.reduce((mem, val) => {
var prgIndex = mem.typeProgramId.findIndex((p) => p.name === val.typeProgramId.name);
updateMem(mem, prgIndex, val);
return mem;
}, {typeProgramId: []});

How would you change values/add to nested object data inside array of objects using Javascript?

const beers = [
{
id: '100',
name: 'stoneys'
},
{
id: '200',
name: 'budweiser'
},
{
id: '300',
name: 'miller'
},
{
id: '400',
name: 'corona'
}
];
const people = [
{
name: 'steve',
teams: [
{
name: 'pirates',
beers: ['100']
},
{
name: 'penguins',
beers: ['300']
}
]
},
{
name: 'jim',
teams: [
{
name: 'indians',
beers: ['200']
},
{
name: 'blue jackets',
beers: ['100', '400']
}
]
}
];
let newPeople = people.map(fan => {
fan.teams.map(team => {
team.beers.map(beer => beers.filter(brand => brand.id === beer)[0])
});
});
Above is a sample I put together to best demonstrate my question. I am having trouble understanding why nested mapping (.map()) of object arrays is not allowing me to alter the nested data. When I console log results, I am either getting an "[undefined, undefined]' or the unchanged "people" array.
I would like to return the same array as "people" except replace the nested "beers" array (people.teams.beers[]) with corresponding objects from the "beers" array. Example of a successful result below:
{
name: 'steve',
teams: [
{
name: 'pirates',
beers: [
{
id: '100',
name: 'stoneys'
}
]
},
{
name: 'penguins',
beers: [
{
id: '300',
name: 'miller'
}
]
}
]
}
Array.map expects a function which takes single array element as parameter and returns a mapped value. In your case you're not returning any value from mapping functions therefore you're getting undefined twice
const beers = [
{
id: '100',
name: 'stoneys'
},
{
id: '200',
name: 'budweiser'
},
{
id: '300',
name: 'miller'
},
{
id: '400',
name: 'corona'
}
];
const people = [
{
name: 'steve',
teams: [
{
name: 'pirates',
beers: ['100']
},
{
name: 'penguins',
beers: ['300']
}
]
},
{
name: 'jim',
teams: [
{
name: 'indians',
beers: ['200']
},
{
name: 'blue jackets',
beers: ['100', '400']
}
]
}
];
let newPeople = people.map(fan => {
let teams = fan.teams.map(team => {
let beer = team.beers.map(beer => beers.filter(brand => brand.id === beer)[0]);
return { name: team.name, beers: beer }
});
return { name: fan.name, teams: teams }
});
console.log(newPeople);

How to merge and return new array from object in es6

Suppose there are two objects.
const a = [
{ id: '1-1-1', name: 'a111' },
{ id: '1-1-2', name: 'a112' },
{ id: '1-2-1', name: 'a121' },
{ id: '1-2-2', name: 'a122' },
{ id: '2-1-1', name: 'a211' },
{ id: '2-1-2', name: 'a212' }
]
const b = ['1-1', '1-2', '2-1']
and the result
{
'1-1':[
{ id: '1-1-1', name: 'a111' },
{ id: '1-1-2', name: 'a112' },
],
'1-2':[
{ id: '1-2-1', name: 'a121' },
{ id: '1-2-2', name: 'a122' },
],
'2-1':[
{ id: '2-1-1', name: 'a211' },
{ id: '2-1-2', name: 'a212' },
]
}
Basically, I want to group the data.
I use includes to check if the item from b to match the id from a. Then construct the new array.
This is my attempt(fiddle):
return b.map(item => a.map(jtem => {
if(jtem.id.includes(item)){
return {
[item]: jtem
}
}
}))
For somehow, it doesn't work.
and, is there a clever way to avoid the nested for loop or map function?
You can do that in following steps:
Apply reduce() on the array b
During each iteration use filter() on the the array a
Get all the items from a which starts with item of b using String.prototype.startsWith()
At last set it as property of the ac and return ac
const a = [
{ id: '1-1-1', name: 'a111' },
{ id: '1-1-2', name: 'a112' },
{ id: '1-2-1', name: 'a121' },
{ id: '1-2-2', name: 'a122' },
{ id: '2-1-1', name: 'a211' },
{ id: '2-1-2', name: 'a212' }
]
const b = ['1-1', '1-2', '2-1']
let res = b.reduce((ac,b) => {
ac[b] = a.filter(x => x.id.startsWith(b));
return ac;
},{})
console.log(res)
As suggested by #Falco is the comments that It would be better to scan over the a once as its large. So here is that version.Actually its better regarding performance
const a = [
{ id: '1-1-1', name: 'a111' },
{ id: '1-1-2', name: 'a112' },
{ id: '1-2-1', name: 'a121' },
{ id: '1-2-2', name: 'a122' },
{ id: '2-1-1', name: 'a211' },
{ id: '2-1-2', name: 'a212' }
]
const b = ['1-1', '1-2', '2-1']
let res = a.reduce((ac,x) => {
let temp = b.find(y => x.id.startsWith(y))
if(!ac[temp]) ac[temp] = [];
ac[temp].push(x);
return ac;
},{})
console.log(res)
Note: startsWith is not supported by I.E. So you can create polyfill using indexOf
if(!String.prototype.startWith){
String.prototype.startsWith = function(str){
return this.indexOf(str) === 0
}
}

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