I have a multi dimensional object array:
var products = [
{ id: 1, groups: [ { id: 1.1, selected: true }, { id: 1.2, selected: false }},
{ id: 2, groups: [ { id: 2.1, selected: false }, { id: 2.2, selected: true }} ];
How can I find list of selected groups (group with selected flag set to true) in a single dimensional array using ES6.
Expected Result:
[1.1, 2.2]
You could use reduce method and inside one more forEach loop to get group objects where selected is true.
var products = [
{ id: 1, groups: [ { id: 1.1, selected: true }, { id: 1.2, selected: false }]},
{ id: 2, groups: [ { id: 2.1, selected: false }, { id: 2.2, selected: true }]} ];
const result = products.reduce((r, {groups}) => {
groups.forEach(e => e.selected && r.push(e.id));
return r;
}, [])
console.log(result)A possible alternative to all the other answers.
Flatten the array, then extract the required info.
const products = [
{ id: 1, groups: [{ id: 1.1, selected: true }, { id: 1.2, selected: false }] },
{ id: 2, groups: [{ id: 2.1, selected: false }, { id: 2.2, selected: true }] }];
const allIds = [].concat(...products.map(p => p.groups)).filter(g => g.selected).map(x => x.id)
console.log(allIds)You can use reduce and filter like below, this will give you all ids that have selected: true. Note that I changed id: 1.2 to be true to demonstrate the ability of getting multiple true results.
const products = [
{ id: 1, groups: [ { id: 1.1, selected: true }, { id: 1.2, selected: true } ]},
{ id: 2, groups: [ { id: 2.1, selected: false }, { id: 2.2, selected: true } ]} ];
const res = products.reduce((a, {groups}) =>
a.concat(...groups.filter(({selected}) => selected).map(({id}) => id))
, []);
console.log(res);
var products = [
{ id: 1, groups: [ { id: 1.1, selected: true }, { id: 1.2, selected: false }]},
{ id: 2, groups: [ { id: 2.1, selected: false }, { id: 2.2, selected: true } ]}];
var desiredResult = products.map(product => {
return product.groups.filter(group => group.selected).map(item => item.id).toString();
});
console.log(desiredResult);
you can make use of map,filter and concat function and get result
var products = [
{ id: 1, groups: [ { id: 1.1, selected: true }, { id: 1.3, selected: true },{ id: 1.2, selected: false }]},
{ id: 2, groups: [ { id: 2.1, selected: false }, { id: 2.2, selected: true }]} ];
const selectgroups = [].concat(...products.map(x => x.groups.filter(g=> g.selected)));
const selectedGroupIds = selectgroups.map(g=> g.id);
console.log(selectedGroupIds);
code which provide list of all selected groups
I see a completely different approach: using specialized data structures to model the data the way you want to work with it:
// Store product id mapped to a set of
// group ids
const productGroupMap = new Map ( [
[ 1, new Set ( [ 1.1, 1.2 ] ) ],
[ 2, new Set ( [ 2.1, 2.2 ] ) ]
] )
// Store group ids to their data
const groupMap = new Map ( [
[ 1.1, { title: "Title 1.1" } ],
[ 1.2, { title: "Title 1.2" } ],
[ 2.1, { title: "Title 2.1" } ],
[ 2.2, { title: "Title 2.2" } ]
] )
// Somewhere in your application, you would declare
// a set of selected group ids, and you would add ids
// when the user selects a given group
const selectedGroups = new Set ()
selectedGroups.add ( 1.1 )
selectedGroups.add ( 2.2 )
// Finally, when you want these selected groups, you just need to
// map selected group ids to their group data getting it from the
// groupMap
const groups = [ ...selectedGroups ].map ( id => groupMap.get ( id ) )
console.log ( groups )