I have a list of objects in following format.
let information = [
{
data: {
list: [ 'item1', 'item4', 'item5'],
}
},
{
data: {
list: [ 'item100', 'item200', 'item300'],
}
},
{
data: {
list: [ 'item1', 'item2', 'item3'],
}
},
{
data: {
list: [ 'item70', 'item71', 'item300'],
}
}
]
I have a dynamic list coming from another selection which could look like this.
const dynamicList = ['item1', 'item71'];
I wish to filter out objects from information where there is at least 1 match when compared to dynamicList.
So in above example, after filtering, I should be left with only 3 items.
Only 2nd item has neither item1 nor item71 in it, so remaining 3 is a match.
Attempted the following to filter.
But the result is 4 so nothing got filtered. Second data has no item1 it in its list.
Why has it not been filtered? Please advice. Thanks.
console.log(information.length); // 4
information = information
.filter(info => info.data.list !== null)
.filter(info => info.data.list
.filter(item => dynamicList.includes(item)));
console.log(information.length); // still 4, should be 3
P.S: Above code can be pasted as it on a browser console to try it out.
You could filter the elements whose list contains at least one element of dynamicList using .some() :
let information = [
{
data: {
list: [ 'item1', 'item4', 'item5'],
}
},
{
data: {
list: [ 'item100', 'item200', 'item300'],
}
},
{
data: {
list: [ 'item1', 'item2', 'item3'],
}
},
{
data: {
list: [ 'item70', 'item71', 'item300'],
}
}
];
const dynamicList = ['item1', 'item71'];
let filteredList = information.filter(info => info.data.list.some(el => dynamicList.includes(el)));
console.log(filteredList);This may be one possible solution to achieve the desired objective:
Code Snippet
const filterUsing = (dlist, iarr) => (
iarr.filter(
({data : { list }}) => list && list.some(x => dlist.some(y => x === y))
)
);
// instead of dlist.some(y => x === y), may also use dlist.includes(x)
const information = [{
data: {
list: ['item1', 'item4', 'item5'],
}
},
{
data: {
list: ['item100', 'item200', 'item300'],
}
},
{
data: {
list: ['item1', 'item2', 'item3'],
}
},
{
data: {
list: ['item70', 'item71', 'item300'],
}
}
];
const dynamicList = ['item1', 'item71'];
console.log('filtered-array:', filterUsing(dynamicList, information));
console.log('length: ', filterUsing(dynamicList, information).length);Explanation
filterUsing takes two params - dlist (dynamicList) and iarr (information array).filter() on iarriarr element to access data.listsome element in list such that the same is present in dlist.