Related
For one of my e-commerce application requirement, I have a nested array of the form (Sample):
const data = [
{
"id": 1,
"group": "upper-wear",
"labels": [
{
"type": "shirts",
"quantity": "20",
},
],
popular: true
},
{
"id": 2,
"group": "bottom-wear",
"lables": [
{
"type": "trousers",
"quantity": "31",
},
],
popular: true
},
]
To this array, I need to insert new objects to the array 'labels' if the group value equals 'upper-wear'.
const newDataToInsert = [
{
"type": 'blazers',
"quantity": 19
},
]
This is what I tried so far, considering that for now I only need to insert to single label (i.e. 'upper-wear') (in future, there can be multiple labels category 'upper-wear', 'bottom-wear', to be inserted into):
const updatedArray = data.map((datum) => {
if (datum.group === 'upper-wear') {
return {
...datum,
labels: [...datum.labels, ...newDataToInsert]
};
}
});
console.log(updatedArray);
But there seems to be a silly issue that I am missing as the result returns like this:
[
{
id: 1,
group: 'upper-wear',
labels: [ [Object], [Object] ],
popular: true
},
undefined
]
I know there may be better approaches available, but this is what I can think of as the minimum solution for now.
any help to resolve the current or any better solution will be highly appreciated.
Try with this
updatedArray = data.map((d) => {
if (d.group && d.group === 'upper-wear') {
return { ...d, labels: d.labels.concat(newDataToInsert) }
} else {
return d;
}
})
const data = [
{
"id": 1,
"group": "upper-wear",
"labels": [
{
"type": "shirts",
"quantity": "20",
},
],
popular: true
},
{
"id": 2,
"group": "bottom-wear",
"lables": [
{
"type": "trousers",
"quantity": "31",
},
],
popular: true
},
];
const newDataToInsert = [
{
"type": 'blazers',
"quantity": 19
},
];
const updatedArray = data.map((d) => {
if (d.group && d.group === 'upper-wear') {
return { ...d, labels: d.labels.concat(newDataToInsert) }
} else {
return d;
}
});
console.log(updatedArray)
Explaination
Here while mapping the data, we check for the condition
IF
If it matches then we will first copy the whole object from the variable b return { ...b }
after that we take another variable with the same name lables return { ...d, labels: d.labels.concat(newDataToInsert) },As per the JSON default nature the new variable with the same name will hold the latest value
Here in labels we first take a copy of old data and then merge it with newDataToInsert array labels: d.labels.concat(newDataToInsert), It will merge 2 arrays and store them in JSON with the name labels
Else
In else we just return the current values else { return d; }
You don't actually need to iterate with map over the array. Just find an object in the array and change what you want.
const data=[{id:1,group:"upper-wear",labels:[{type:"shirts",quantity:"20"}],popular:true},{id:2,group:"bottom-wear",lables:[{type:"trousers",quantity:"31"}],popular:true}];
const newDataToInsert=[{type:"blazers",quantity:19}];
data.find(({ group }) => group === 'upper-wear')?.labels.push(...newDataToInsert);
console.log(data);
.as-console-wrapper { max-height: 100% !important; top: 0; }
You're not returning all objects from your map. you're only returning a result when your criteria is met. This is resulting in your undefined objects...
const data = [
{ "id": 1, "group": "upper-wear", "labels": [ { "type": "shirts", "quantity": "20", }, ], popular: true },
{ "id": 2, "group": "bottom-wear", "lables": [ { "type": "trousers", "quantity": "31", }, ], popular: true },
]
const newDataToInsert = [ { "type": 'blazers',"quantity": 19 }, ]
const updatedArray = data.map(datum => {
if (datum.group === 'upper-wear') datum.labels = [...datum.labels, ...newDataToInsert]
return datum
});
console.log(updatedArray);
You can use Array#find to locate the desired group and then change labels for the group found. There are two options depending on how many items you would like to insert. Use Array#push to add the desired item; use forEach for more than one item:
const searchgroup = "upper-wear";
const target = data.find(({group}) => group === searchgroup);
target.labels.push(...newDataToInsert); //For one item to insert
//newDataToInsert.forEach(label => target.labels.push( label )); //For more than one item
const data = [{"id": 1, "group": "upper-wear", "labels": [{"type": "shirts", "quantity": "20"},],popular: true }, {"id": 2, "group": "bottom-wear", "lables": [{"type": "trousers", "quantity": "31", },],popular: true}];
const newDataToInsert = [{"type": 'blazers', "quantity": 19}];
//group to find
const searchgroup = "upper-wear";
//target element in data
const target = data.find(({group}) => group === searchgroup);
//check if group was found
if( target ) {
//if there's only one product in newDataToInsert us this:
//target.labels.push(...newDataToInsert);
//if you have more than one product to be inserted use this; also works for one
newDataToInsert.forEach(label => target.labels.push( label ));
} else {
console.log( `No such group found: ${searchgroup}!` );
}
console.log( data );
there is a list of users
filterData = [
{
"position":"lawyer",
"department_positions":[],
"group_positions":[
{"group":{"id":2,"code":"234","name":"group1"},"lead":false},
{"group":{"id":1,"code":"123","name":"group12"},"lead":true}
]
},
{
"position":"director",
"department_positions":[
{"department":{"id":3,"code":"333","name":"subDep"},"lead":false}
],
"group_positions":[
{"group":{"id":2,"code":"234","name":"group1"},"lead":false},
{"group":{"id":1,"code":"123","name":"group12"},"lead":true}
]
},
{
"position":"director",
"department_positions":[],
"group_positions":[]
}
]
and list of filters
categories = {
"position":["lawyer","director"],
"group_positions":["group1","group12"],
"department_positions":["generalDep", "subDep"]
}
It is necessary to filter users taking into account the fact that several filters can be selected at the same time. For example, i want to find user with position = "director" and AND group_positions = "group1" AND department_positions = "subDep"
my code doesn't allow filtering by multiple conditions. how can i fix it?
this.filter = this.filterData.filter(item => {
for (let key in this.categories) {
if (item[key].find(el =>
this.categories[key].includes(
el.group?.name || el.department?.name
)
)) {
return true
}
}
return false
})}
This is a good place to employ an es6 class to give behavior to the object being filtered. Augment each object to determine if it matches the "category" object.
(from the example data, this assumes the OP is looking for a "product of sums" match: for all of the category keys match at least one of the category values)
class FilterMe {
constructor(item) {
Object.assign(this, item);
}
namesForKey(key) {
switch (key) {
case 'position':
return [this.position]; // always answer an array
case 'group_positions':
return this.group_positions.map(gp => gp.group.name);
case 'department_positions':
return this.department_positions.map(dp => dp.department.name);
default:
return [];
}
}
// return true if a single filter key-value pair is matched
matchesFilterKeyValue(filterKey, filterOptions) {
const myNames = this.namesForKey(filterKey);
const matches = filterOptions.filter(e => myNames.includes(e));
return matches.length > 0;
}
// return true if all filter key-values pairs are matched
matchesFilter(filter) {
return Object.entries(filter).every(keyValue => {
return this.matchesFilterKeyValue(...keyValue);
})
}
}
const filterData = [{
"position": "lawyer",
"department_positions": [],
"group_positions": [{
"group": {
"id": 2,
"code": "234",
"name": "group1"
},
"lead": false
}, {
"group": {
"id": 1,
"code": "123",
"name": "group12"
},
"lead": true
}]
},
{
"position": "director",
"department_positions": [{
"department": {
"id": 3,
"code": "333",
"name": "subDep"
},
"lead": false
}],
"group_positions": [{
"group": {
"id": 2,
"code": "234",
"name": "group1"
},
"lead": false
}, {
"group": {
"id": 1,
"code": "123",
"name": "group12"
},
"lead": true
}]
},
{
"position": "director",
"department_positions": [],
"group_positions": []
}
]
const categories = {
"position": ["lawyer", "director"],
"group_positions": ["group1", "group12"],
"department_positions": ["generalDep", "subDep"]
}
// convert the filterData to the objects and test them...
let objects = filterData.map(d => new FilterMe(d));
let matches = objects.filter(o => o.matchesFilter(categories))
console.log(matches)
You can try something like this:
let filtered = example.filter(item => {
let valid = false
if (item.includes('something')) {
valid = true
}
if (!valid) {
// check second condition
}
return valid
})
Use a temporary placeholder so you don't immediately have to return true/false.
I get an input like this:
input 1:
{
"name": "Ben",
"description": "Ben",
"attributes": [
{
"type": "Background",
"value": "Default"
},
{
"type": "Hair-color",
"value": "Brown"
}
]
}
input 2
{
"name": "Ice",
"description": "Ice",
"attributes": [
{
"type": "Background",
"value": "Green"
},
{
"type": "Hair-color",
"value": "White"
}
]
}
input 3
{
"name": "Itay",
"description": "Itay",
"attributes": [
{
"type": "Background",
"value": "Default"
},
{
"type": "Hair-color",
"value": "Brown"
}
]
}
What I want to do is count the amount of each type of background and each type of hair-color appearing.
(These are sample examples and in reality there are more types and different values)
Let's say in these examples we have 2 objects that have a background as default then I want to have a count of that like so:
export interface TraitCount {
value: string,
count: number
}
export interface CountOfEachAttribute {
trait_type: string,
trait_count: traitCount[] | null,
total_variations: number
}
I want the most effective code because there are other aspects to the code, in addition it will run on 5-10k queries not just three, so needs
to run in good times too :D
(It's similar to my other question done with python but now I need it in js also)
Atm it's something like this:
(Apart of a much bigger code so keep that in mind)
setInitalCountOfAllAttribute( state, { payload }: PayloadAction<CountOfEachAttribute[] | null> ) {
if (payload === null) {
state.countOfAllAttribute = null;
} else {
state.countOfAllAttribute = payload;
}
},
setCountOfAllAttribute(state, { payload }: PayloadAction<Attribute>) {
if (state.countOfAllAttribute !== null) {
state.countOfAllAttribute.map(
(countOfEachAttribute: CountOfEachAttribute) => {
// Find the trait type
if (countOfEachAttribute.trait_type === payload.trait_type) {
// initiate the trait count array to store all the trait values and add first trait value
if (countOfEachAttribute.trait_count === null) {
const new_trait_count = { value: payload.value, count: 1 };
countOfEachAttribute.trait_count = [new_trait_count];
countOfEachAttribute.total_variations++;
}
// Trait array already existed.
else {
// Check if value already present or not
const checkValue = (obj: any) => obj.value === String(payload.value);
const isPresent = countOfEachAttribute.trait_count.some(checkValue)
const isPresent2 = countOfEachAttribute.trait_count.find((elem: any) => elem.value === String(payload.value))
// Value matched, increase its count by one
if (isPresent2) {
countOfEachAttribute.trait_count &&
countOfEachAttribute.trait_count.map((trait) => {
if (trait.value === payload.value) {
trait.count++;
}
});
}
// Value doesn't match, add a new entry and increase the count of variations by one
else {
const new_trait_count = { value: payload.value, count: 1 };
countOfEachAttribute.trait_count = [
...countOfEachAttribute.trait_count,
new_trait_count,
];
countOfEachAttribute.total_variations++;
}
}
}
}
);
}
},
You can merge all arrays and use Array.reduce.
const input1 = {
"name": "Ben",
"description": "Ben",
"attributes": [{
"type": "Background",
"value": "Default"
},
{
"type": "Hair-color",
"value": "Brown"
}
]
}
const input2 = {
"name": "Ice",
"description": "Ice",
"attributes": [{
"type": "Background",
"value": "Green"
},
{
"type": "Hair-color",
"value": "White"
}
]
}
const input3 = {
"name": "Itay",
"description": "Itay",
"attributes": [{
"type": "Background",
"value": "Default"
},
{
"type": "Hair-color",
"value": "Brown"
}
]
}
const mergedInput = [input1, input2, input3];
const result = mergedInput.reduce((acc, item) => {
item.attributes.forEach(attrItem => {
const existType = acc.find(e => e.trait_type == attrItem.type);
if (existType) {
var existAttr = existType.trait_count.find(e => e.value == attrItem.value);
if (existAttr) {
existAttr.count++;
} else {
existType.trait_count.push({
value: attrItem.value,
count: 1
});
existType.total_variations++;
}
} else {
acc.push({
trait_type: attrItem.type,
trait_count: [{
value: attrItem.value,
count: 1
}],
total_variations: 1
})
}
});
return acc;
}, []);
console.log(result);
I suggest instead of creating an array for trait_count to make it an object so you don't have to iterate over it whenever you are adding a new attribute. In the snippet below I'm using the value of the attribute as a sort of hash that allows the access to the given property without having to call the Array.prototype.find function
const input1 = {"name":"Ben","description":"Ben","attributes":[{"type":"Background","value":"Default"},{"type":"Hair-color","value":"Brown"}]};
const input2 = {"name":"Ice","description":"Ice","attributes":[{"type":"Background","value":"Green"},{"type":"Hair-color","value":"White"}]};
const input3 = {"name":"Itay","description":"Itay","attributes":[{"type":"Background","value":"Default"},{"type":"Hair-color","value":"Brown"}]};
function countAtributes(input, totalCounts={}) {
input.attributes.forEach((attribute) => {
if (!totalCounts[attribute.type])
totalCounts[attribute.type] = {trait_type: attribute.type, trait_count: {}, total_variations: 0};
if (!totalCounts[attribute.type].trait_count[attribute.value]) {
totalCounts[attribute.type].trait_count[attribute.value] = {value: attribute.value, count: 1};
totalCounts[attribute.type].total_variations+=1;
}
else totalCounts[attribute.type].trait_count[attribute.value].count +=1;
})
}
const totalCounts = {};
countAtributes(input1, totalCounts);
countAtributes(input2, totalCounts);
countAtributes(input3, totalCounts);
console.log(totalCounts);
It could be turned into the array afterwards with Object.values if necessary
I believe it is a much better approach to what you had before as you don't have to iterate over the tables of trait_counts. In theory it should significantly reduce the time taken. Iterating over the array and checking a condition each time is much slower than key lookup in Javascript object
In Javascript, how to retrieve an object in an array by one of its property ?
Hi all,
let's assume that we have the below :
"Attributes":[
{
"Name":"Brief",
"Value":"This skirt was fabriced from ...."
},
{
"Name":"Details",
"Value":"Measurements and Pictures are real"
},
{
"Name":"SKUNumber",
"Value":"12345678"
}
]
What I need to do is to get the value of "Value" based on "Name"..
For example :
console.log(Attributes.Brief) ==> "This skirt was fabriced from ...."
So I need a function to help doing that
Note that I don't want to use the index of the object, because its order may changed.
Thank you
Well, it's always better to show what you have attempted rather than just asking..
You can use Array.find to achieve this
let Attributes = [
{
"Name":"Brief",
"Value":"This skirt was fabriced from ...."
},
{
"Name":"Details",
"Value":"Measurements and Pictures are real"
},
{
"Name":"SKUNumber",
"Value":"12345678"
}
]
function getValueByName(name) {
return Attributes.find(d => d.Name.toLowerCase() == name.toLowerCase()).Value
}
console.log(getValueByName('Brief'))
console.log(getValueByName('details'))
console.log(getValueByName('SKUNumber'))
One option you have is to use Array.prototype.filter:
const d = [{
"Name": "Brief",
"Value": "This skirt was fabriced from ...."
},
{
"Name": "Details",
"Value": "Measurements and Pictures are real"
},
{
"Name": "SKUNumber",
"Value": "12345678"
}
]
console.log(d.filter(x=>x.Name==="Brief")[0].Value)
You can also make it more generic:
const d = [{
"Name": "Brief",
"Value": "This skirt was fabriced from ...."
},
{
"Name": "Details",
"Value": "Measurements and Pictures are real"
},
{
"Name": "SKUNumber",
"Value": "12345678"
}
]
const getValOfXfromArrByValOfY = (arr, x, y, val) => arr.find(z => z[y] === val)[x]
console.log(getValOfXfromArrByValOfY(d, 'Value', 'Name', 'SKUNumber'))
You could use a Proxy with a getter for the key, which returns a find of the object with the value.
var object = { attributes: [{ Name: "Brief", Value: "This skirt was fabriced from ...." }, { Name: "Details", Value: "Measurements and Pictures are real" }, { Name: "SKUNumber", Value: "12345678" }] },
attributes = new Proxy(
object.attributes,
{ get: (array, prop) => (array.find(({ Name }) => Name === prop) || {}).Value }
);
console.log(attributes.Brief);
console.log(attributes.SKUNumber);
You can use javascript find function see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/find see bellow sample code:
var Attributes =[
{
"Name":"Brief",
"Value":"This skirt was fabriced from ...."
},
{
"Name":"Details",
"Value":"Measurements and Pictures are real"
},
{
"Name":"SKUNumber",
"Value":"12345678"
}
]
var found = Attributes.find(function(element) {
return element.Name == "Details";
});
console.log(found.Value); //output : Measurements and Pictures are real
I'd like to map this table's chapter_id and brother_id with the brothers and chapters table below and return the brothername and name field's respectively. Using js or jquery. I am using vuejs returning minutes array as a computed property. See below.
In sql it's be something like
select brothername from brothers where minute.brother_id = brothers.id ... and then set the brothername as the new value for brother_id
same thing goes for chapter_id:
select brothername from brothers where minute.brother_id = brothers.id ... and then set the brothername as the new value for brother_id
the resulting array or object should be:
Expected Array
[
{
"location":"UCLA",
"chapter_id":"Beta",
"brother_id":"Golpher",
"created_at":"2008-05-15 22:23:00",
"status":"Approved"
},
{ ... },
{
"location":"John's Deli",
"chapter_id":"Beta", notice the change in the array based on the ids
"brother_id":"Sheera", notice the change in the array based on the ids
"created_at":"2008-05-15 22:23:00",
"status":"Approved"
}
]
Minutes Table (original array)
[
{
"location":"UCLA",
"chapter_id":2,
"brother_id":1,
"created_at":"2008-05-15 22:23:00",
"status":"Approved"
},
{ ... },
{
"location":"John's Deli",
"chapter_id":2,
"brother_id":4,
"created_at":"2008-05-15 22:23:00",
"status":"Approved"
}
]
Chapter's Table
[
{
"id":1,
"letter_representation":"A",
"name":"Alpha",
"founded_at":"UCLA",
...
},
{ ... }
]
Brother's Table
[
{
"id":1,
"profile_id":1,
"chapter_id":1,
"brothername":"Golpher",
"firstname":"Jack",
...
},
{ ... },
{
"id":4,
"profile_id":4,
"chapter_id":1,
"brothername":"Sheera",
"firstname":"Jake",
...
}
]
Vue.js
computed: {
brothers () {
return this.$store.state.brothers
},
chapters () {
return this.$store.state.chapters
},
minutes () {
return this.$store.getters.model
}
},
I assume that you don't want to mutate objects in the original arrays with this operation.
Note You may want to handle the case where brother_id or chapter_id doesn't exist in the corresponding table. In the below example, it just sets the property value to undefined
const minutesTable = [{
"location": "UCLA",
"chapter_id": 2,
"brother_id": 1,
"created_at": "2008-05-15 22:23:00",
"status": "Approved"
}, {
"location": "John's Deli",
"chapter_id": 2,
"brother_id": 4,
"created_at": "2008-05-15 22:23:00",
"status": "Approved"
}]
const chapterTable = [{
"id": 1,
"letter_representation": "A",
"name": "Alpha",
"founded_at": "UCLA",
}]
const brotherTable = [{
"id": 1,
"profile_id": 1,
"chapter_id": 1,
"brothername": "Golpher",
"firstname": "Jack",
}, {
"id": 4,
"profile_id": 4,
"chapter_id": 1,
"brothername": "Sheera",
"firstname": "Jake",
}]
// your result
const result = minutesTable.map(m => {
const brother = brotherTable.find(b => b.id === m.brother_id)
const chapter = chapterTable.find(c => c.id === m.chapter_id)
return Object.assign({}, m, {
brother_id: brother && brother.brothername,
chapter_id: chapter && chapter.name,
})
})
console.log(result)
This should be what you need
const minutesTable = [
{
"location":"UCLA",
"chapter_id":2,
"brother_id":1,
"created_at":"2008-05-15 22:23:00",
"status":"Approved"
},
{
"location":"John's Deli",
"chapter_id":2,
"brother_id":4,
"created_at":"2008-05-15 22:23:00",
"status":"Approved"
}
]
const chapterTable =
[
{
"id":1,
"letter_representation":"A",
"name":"Alpha",
"founded_at":"UCLA",
}
]
const brotherTable = [
{
"id":1,
"profile_id":1,
"chapter_id":1,
"brothername":"Golpher",
"firstname":"Jack",
},
{
"id":4,
"profile_id":4,
"chapter_id":1,
"brothername":"Sheera",
"firstname":"Jake",
}
]
/* code starts here */
let newMinutesTable = JSON.parse(JSON.stringify(minutesTable)).map(a => {
let brother = brotherTable.find(id => id.id === a.brother_id);
let chapter = chapterTable.find(id => id.id === a.chapter_id)
if (brother) a.brother_id = brother.brothername
if (chapter) a.chapter_id = chapter.name;
return a;
})
console.log([minutesTable,newMinutesTable]);
I think you should prepare those values first just to better understanding. So I made this, let me explain in pieces.
Your input information:
var minutesTable = [{
"location": "UCLA",
"chapter_id": 2,
"brother_id": 1,
"created_at": "2008-05-15 22:23:00",
"status": "Approved"
}, {
"location": "John's Deli",
"chapter_id": 2,
"brother_id": 4,
"created_at": "2008-05-15 22:23:00",
"status": "Approved"
}],
chapterTable = [{
"id": 1,
"letter_representation": "A",
"name": "Alpha",
"founded_at": "UCLA",
}],
brotherTable = [{
"id": 1,
"profile_id": 1,
"chapter_id": 1,
"brothername": "Golpher",
"firstname": "Jack",
}, {
"id": 4,
"profile_id": 4,
"chapter_id": 1,
"brothername": "Sheera",
"firstname": "Jake",
}];
Somehow you'll be forced to take this information as variables. We will work with that.
Preparing data
Dealing with array of objects it's a litle bit complicated when you need to look for unique informations on each object from distinct arrays especially if you want to run this more than once. So instead of working with arrays of objects we can save our lifes changing that to objects of objects, where each item index must be that unique IDs. Look:
var chapters = {},
brothers = {};
chapterTable.map(function(el, i) {
chapters[el.id] = el;
});
brotherTable.map(function(el, i) {
brothers[el.id] = el;
});
Now you can easily find a chapter by chapter_id or a brother by brother_id, right? Then you can finish the problem like this:
var output = [];
minutesTable.map(function(el, i) {
var item = {
"location": el.location, // note that values are just default values, just in case
"chapter_id":"-",
"brother_id":"-",
"created_at": el.created_at,
"status": el.status
};
// PS: you need to check if that brother_id really exists!
if(brothers[el.brother_id] != undefined) {
item.brother_id = brothers[el.brother_id].brothername;
}
// PS: the same with chapters
if(chapters[el.chapter_id] != undefined) {
item.chapter_id = chapters[el.chapter_id].name;
}
output.push(item);
});
That's it. Anyway, if you can change your SQL queries, would be better to work with SQL joins and prepare your values there.