I have a nested object array like below,
data = [
{
"field": "A",
"items": [
{
"Id": 001,
"ItemDescription": "item 1"
}
]
},
{
"field": "A",
"items": [
{
"Id": 002,
"ItemDescription": "item 2"
},
{
"Id": 003,
"ItemDescription": "item 3"
},
{
"Id": 004,
"ItemDescription": "item 4"
}
]
}
]
I am trying to fetch only the inner object array from the object array.
I have tried different ways to fetch the inner object array from object array,
data.map((u,i) => u[i].map((a,b)=> a.items))
expected result:
data = [
{
"Id": 001,
"ItemDescription": "item 1"
},
{
"Id": 002,
"ItemDescription": "item 2"
},
{
"Id": 003,
"ItemDescription": "item 3"
},
{
"Id": 004,
"ItemDescription": "item 4"
}
]
You can use map and flat
let data = [
{
"field": "A",
"items": [
{
"Id": 001,
"ItemDescription": "item 1"
}
]
},
{
"field": "A",
"items": [
{
"Id": 002,
"ItemDescription": "item 2"
},
{
"Id": 003,
"ItemDescription": "item 3"
},
{
"Id": 004,
"ItemDescription": "item 4"
}
]
}
]
let result = data.map(d => d.items).flat();
console.log(result);
Output
Just use a single .map to get the values in the items array
let newArr = data.map((u,i) => u.items)
console.log(newArr)
and to return all the values in one single array use .flat
console.log(newArr.flat())
Related
I have a following data structure, array of dictionaries
[
{
"id": 1,
"name": "Some Name 1",
"topics": [
{
"id": 3,
"name": "Topic Name",
"topics": [],
},
{
"id": 3,
"name": "Topic Name",
"topics": [],
}
]
},
{
"id": 2,
"name": "Some Name 2",
"topics": [
{
"id": 3,
"name": "Topic Name",
"topics": [],
},
{
"id": 3,
"name": "Topic Name",
"topics": [],
}
]
},
[
{
"id": 1,
"name": "Some Name 2",
"topics": [
{
"id": 1,
"name": "Topic Name 1",
"topics": [],
},
{
"id": 2,
"name": "Topic Name 2",
"topics": [],
}
]
},
{
"id": 2,
"name": "Some Name 1",
"topics": [
{
"id": 3,
"name": "Topic Name",
"topics": [],
},
{
"id": 3,
"name": "Topic Name",
"topics": [],
}
]
},
I want to essentially be able to combine the arrays within each dictionary if I have the same id, so for each dictionary i will have higher level dictionary items being the same and essentially combine those together to avoid duplication. Preferably i would like it to be recursively being that in case the topics within topics are also duplicate (you can assume the order is always respected).
I would appreciate if you could share a solution to this
I have an array of objects with duplicates:
[
{
"code": "d1",
"title": "Title 1"
},
{
"code": "d2",
"title": "Title 2"
},
{
"code": "d3",
"title": "Title 3"
},
{
"code": "d4",
"title": "Title 4"
},
{
"code": "d4",
"title": "Title 4"
},
{
"code": "d3",
"title": "Title 3"
}
]
So i want the output to be having only the once which doesn't have duplicates included like below:
[
{
"code": "d1",
"title": "Title 1"
},
{
"code": "d2",
"title": "Title 2"
}
]
Any help would be appreciated, Thanks!
Find unique's values in an array.
const ressult = YourArray.filter(
(value, index, array) => array.findIndex((v) => v.code === value.code) === index
);
Here is one way of doing it:
const products=[
{
"code": "d1",
"title": "Title 1"
},
{
"code": "d2",
"title": "Title 2"
},
{
"code": "d3",
"title": "Title 3"
},
{
"code": "d4",
"title": "Title 4"
},
{
"code": "d4",
"title": "Title 4"
},
{
"code": "d3",
"title": "Title 3"
}
];
const res=Object.entries(products.reduce((a,c)=>{
(a[c.code+"|"+c.title]??=[]).push(c);
return a;
},{})).reduce((a,[k,v])=>{
if(v.length==1) a.push(v[0]);
return a;
},[]);
console.log(res);
My approach involves two .reduce() loops:
In the first one I generate an object that collects all elements of the original array behind a compound key made up of the properties of the elements.
the object is then converted into an array again with Object.entries()
and in a second .reduce() only those elements will be collected (i. e.: their first element) into the target array that have a length of 1
let val = [
{
"code": "d1",
"title": "Title 1"
},
{
"code": "d2",
"title": "Title 2"
},
{
"code": "d3",
"title": "Title 3"
},
{
"code": "d4",
"title": "Title 4"
},
{
"code": "d4",
"title": "Title 4"
},
{
"code": "d3",
"title": "Title 3"
}
];
let distinctVal = getDistincts(val);
function getDistincts(val){
let obj={};
for (let i = 0; i < val.length; i++) {
obj[`${val[i]["code"]}`]=val[i]["title"];
}
return obj;
}
console.log(distinctVal);
I have two arrays of objects that I need to combine where the nested ID (connect.id) of the second array matches the id of the first but can't see how to do it
can anyone help?
const arr1 = [
{ "id": 7619209572755, "title": "Title 1" },
{ "id": 7619209157372, "title": "Title 2" },
{ "id": 7619209921625, "title": "Title 3" }
];
const arr2 = [
{
"id": 7619217289192,
"connect": [
{ "id": 7619209157372, "title": "Title 1" }
],
"value": "1"
},
{
"id": 7619217242206,
"connect": [
{ "id": 7619209921625, "title": "Title 2" }
],
"value": "2"
}
];
const expectedResult = [
{ "id": 7619209572755, "title": "Title 1" },
{ "id": 7619209157372, "title": "Title 2", "value": "1" },
{ "id": 7619209921625, "title": "Title 3", "value": "2" }
]
Using Array#reduce, iterate over arr2 to map every connect element's id with the its object's value in a Map
Using Array#map, iterate over arr1, if an element's id is in the map, set its value
const
arr1 = [ { "id": 7619209572755, "title": "Title 1" }, { "id": 7619209157372, "title": "Title 2" }, { "id": 7619209921625, "title": "Title 3" } ],
arr2 = [
{
"id": 7619217289192,
"connect": [ { "id": 7619209157372, "title": "Title 1" } ],
"value": "1",
},
{
"id": 7619217242206,
"connect": [ { "id": 7619209921625, "title": "Title 2" } ],
"value": "2",
}
];
const connectValueMap = arr2.reduce((map, { connect = [], value}) => {
connect.forEach(({ id }) => map.set(id, value));
return map;
}, new Map);
const merged = arr1.map(e => {
const value = connectValueMap.get(e.id);
if(value) e.value = value;
return e;
});
console.log(merged);
I have a nested array of objects and want to get only the child property elements of an array with the title of the parent element prepended to the title in the child. This is just an example and the actual data will include a unique children property in separate indices in the array.
I would like to implement flatMap in my solution instead of using flattenDeep and map from lodash. Please advice.
const headers = [{
"id": "name1",
"title": "Name 1",
"children": [{
"title": "Children 1",
"child": [{
"title": "Child 1",
"onClick": "child1Click"
}, {
"title": "Child 2",
"onClick": "child2Click"
}]
}, {
"title": "CHildren 2",
"child": [{
"title": "Child 3",
"id": "child3Click"
}, {
"title": "Child 4",
"id": "child4Click"
}]
}]
}, {
"id": "name2",
"title": "Name 2",
"children": [{
"title": "Children 3",
"child": [{
"title": "Child 5",
"onClick": "child5Click"
}, {
"title": "Child 6",
"onClick": "child6Click"
}]
}, {
"title": "CHildren 4",
"child": [{
"title": "Child 7",
"id": "child7Click"
}, {
"title": "Child 8",
"id": "child8Click"
}]
}]
}, {
"id": "name3",
"title": "Name 3"
}, {
"id": "name4",
"title": "Name 4"
}]
console.log(_.flattenDeep(_.map(_.flattenDeep(_.compact(_.map(headers, item => item.children))), item => _.map(item.child, child => {
return {
...child,
title: `${item.title} ${child.title}`
}
}))))
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.15/lodash.min.js"></script>
The output I expect is
[
{
"title": "Children 1 Child 1",
"onClick": "child1Click"
},
{
"title": "Children 1 Child 2",
"onClick": "child2Click"
},
{
"title": "CHildren 2 Child 3",
"id": "child3Click"
},
{
"title": "CHildren 2 Child 4",
"id": "child4Click"
},
{
"title": "Children 3 Child 5",
"onClick": "child5Click"
},
{
"title": "Children 3 Child 6",
"onClick": "child6Click"
},
{
"title": "CHildren 4 Child 7",
"id": "child7Click"
},
{
"title": "CHildren 4 Child 8",
"id": "child8Click"
}
]
Any help is greatly appreciated. Thanks
You can solve this with just reduce and two inner forEach loops for children and child.
const headers = [{"id":"name1","title":"Name 1","children":[{"title":"Children 1","child":[{"title":"Child 1","onClick":"child1Click"},{"title":"Child 2","onClick":"child2Click"}]},{"title":"CHildren 2","child":[{"title":"Child 3","id":"child3Click"},{"title":"Child 4","id":"child4Click"}]}]},{"id":"name2","title":"Name 2","children":[{"title":"Children 3","child":[{"title":"Child 5","onClick":"child5Click"},{"title":"Child 6","onClick":"child6Click"}]},{"title":"CHildren 4","child":[{"title":"Child 7","id":"child7Click"},{"title":"Child 8","id":"child8Click"}]}]},{"id":"name3","title":"Name 3"},{"id":"name4","title":"Name 4"}]
const result = headers.reduce((r, {children}) => {
children && children.forEach(({title: pTitle, child}) => {
child && child.forEach(({title, ...rest}) => r.push({
title: `${pTitle} ${title}`,
...rest
}))
})
return r;
}, [])
console.log(result)
I have 2 arrays objects and I need to do a count of home many types of card we have.
The first object contains all the car id's and the second list contains the types of cars.
Here is the data:
var arr = {
"categories": [{
"id": "100",
"name": "category name",
"car_id": "1"
}, {
"id": "192",
"name": "category name here",
"car_id": "25"
}, {
"id": "192",
"name": "category name here",
"car_id": "27"
}]
};
var arr2 = {
"cars": [{
"id": "1",
"name": "car name",
"car_id": "1",
"type": "ford"
}, {
"id": "4",
"name": "name 2",
"car_id": "25",
"type": "ford"
}, {
"id": "4",
"name": "name 2",
"car_id": "27",
"type": "fiat"
}]
};
There's only 5 types of cars so I have 5 variables:
var:
ford,
fiat,
mazda,
mini,
mg
So, what I need to end up with is something like this:
ford: 2;
fiat: 1;
mazda: 0;
mini: 0;
mg: 0;
How can I do this?
If your number of types are fixed, then try this approach
Make an map first
var map = {
ford: 0,
fiat: 0,
mazda: 0,
mini: 0,
mg: 0
};
Now iterate the arrays and count by types
arr2.cars.forEach( function( item ){
map[ item.type ]++;
});
your map is populated with the values now.
var arr2 = {
"cars": [{
"id": "1",
"name": "car name",
"car_id": "1",
"type": "ford"
}, {
"id": "4",
"name": "name 2",
"car_id": "25",
"type": "ford"
}, {
"id": "4",
"name": "name 2",
"car_id": "27",
"type": "fiat"
}]
};
var map = {
ford: 0,
fiat: 0,
mazda: 0,
mini: 0,
mg: 0
};
arr2.cars.forEach(function(item) {
map[item.type] ++;
});
console.log(map);
var arr = {
"categories": [{
"id": "100",
"name": "category name",
"car_id": "1"
}, {
"id": "192",
"name": "category name here",
"car_id": "25"
}, {
"id": "192",
"name": "category name here",
"car_id": "27"
}]
};
var arr2 = {
"cars": [{
"id": "1",
"name": "car name",
"car_id": "1",
"type": "ford"
}, {
"id": "4",
"name": "name 2",
"car_id": "25",
"type": "ford"
}, {
"id": "4",
"name": "name 2",
"car_id": "27",
"type": "fiat"
}]
};
var carCount, typeCount;
arr.categories.forEach(function(item){
if(item.hasOwnProperty("car_id")){
carCount = arr.categories.length;
}
});
arr2.cars.forEach(function(item){
if(item.hasOwnProperty("type")){
typeCount = arr2.cars.length;
}
});
console.log(carCount);
console.log(typeCount);
https://jsfiddle.net/Law7rzc2/
All you need is
countBy(arr2.cars, 'type')
The implementation of countBy is left as an exercise.
Array.prototype.reduce is your go-to for this kind of array computation. A Map will help you keep track of unique car makes as you iterate thru the array of cars.
var obj2 = {
"cars": [{
"id": "1",
"name": "car name",
"car_id": "1",
"type": "ford"
}, {
"id": "4",
"name": "name 2",
"car_id": "25",
"type": "ford"
}, {
"id": "4",
"name": "name 2",
"car_id": "27",
"type": "fiat"
}]
};
const typeStat = cars => {
let map = cars.reduce((m, {type}) =>
m.set(type, (m.get(type) || 0) + 1), new Map());
return Array.from(map, ([make, count]) => ({make, count}));
};
let stats = typeStat(obj2.cars)
console.log(stats);
Output
[
{
"make": "ford",
"count": 2
},
{
"make": "fiat",
"count": 1
}
]