I have the following object:
const myObject = {
"-Lz8YxHiwp8QZW3TqAFn": Object {
"first": "Breanna",
"last": "Blah",
},
"-Lz8YxHqQXWoaGOFRLrO": Object {
"first": "Joshua",
"last": "Blah",
},
"-Lz8YxHsMItaaTVNyQRE": Object {
"first": "Joziah",
"last": "Blah",
},
"-Lz8YxHwuVBMWl0Go6C5": Object {
"first": "Lino",
"last": "Blah",
},
"-Lz8YxHy0S-QkDaE1PkX": Object {
"first": "Rebecca",
"last": "Blah",
},
"-Lz8YxI5IItUiXX6rFn_": Object {
"first": "Rosario",
"last": "Blah",
},
"-Lz8YxIB_YTBF8liL855": Object {
"first": "Alissa",
"last": "Blah",
}
}
then I have a set with the following:
const mySet = {
"-Lz8YxMp-V0TfiwrkM49",
"-Lz8YxNQP2WkkO0qpkRJ",
"-Lz8YxHy0S-QkDaE1PkX",
"-MmFNgjyopU3E8z5g-zU",
"-Lz8YxLVi_uZp_RkcRIH",
"-MuEgimJOIbPw3GyKBJ3",
"-Lz8YxOFpVHx2xPI1mUu",
"-Lz8YxJ-_wuk8bmEyvGT",
"-Lz8YxKj5WXY1oNwylQ4",
"-Lz8YxN87U1YM6_fKgq1",
"-Lz8YxOI4qszJvZhrSde",
"-Lz8YxI5IItUiXX6rFn_",
}
I need to return myObject with ONLY the objects that match an item in mySet. I have done this with a map but it turns myObject into an array. The following uses map and returns an array which I can't use for this particular situation.
// const addGroupMembers = Object.entries(members)
// .filter(([key]) => {
// eachHit++;
// console.log(key)
// return attendanceGroupMembers.has(key);
// })
// .map(([_, members]) => {
// eachHit++;
// console.log('in map')
// return members;
// });
I would like to retain the myObject structure but with only the items found. Any idea how I can accomplish this?
You could convert myObject into an array of entries using Object.entries() then use Set.has() along with Array.filter(), and finally use Object.fromEntries() to convert the filtered array of entries back into an object:
const myObject = {
"-Lz8YxHiwp8QZW3TqAFn": { first: "Breanna", last: "Blah" },
"-Lz8YxHqQXWoaGOFRLrO": { first: "Joshua", last: "Blah" },
"-Lz8YxHsMItaaTVNyQRE": { first: "Joziah", last: "Blah" },
"-Lz8YxHwuVBMWl0Go6C5": { first: "Lino", last: "Blah" },
"-Lz8YxHy0S-QkDaE1PkX": { first: "Rebecca", last: "Blah" },
"-Lz8YxI5IItUiXX6rFn_": { first: "Rosario", last: "Blah" },
"-Lz8YxIB_YTBF8liL855": { first: "Alissa", last: "Blah" },
};
const mySet = new Set([
"-Lz8YxMp-V0TfiwrkM49",
"-Lz8YxNQP2WkkO0qpkRJ",
"-Lz8YxHy0S-QkDaE1PkX",
"-MmFNgjyopU3E8z5g-zU",
"-Lz8YxLVi_uZp_RkcRIH",
"-MuEgimJOIbPw3GyKBJ3",
"-Lz8YxOFpVHx2xPI1mUu",
"-Lz8YxJ-_wuk8bmEyvGT",
"-Lz8YxKj5WXY1oNwylQ4",
"-Lz8YxN87U1YM6_fKgq1",
"-Lz8YxOI4qszJvZhrSde",
"-Lz8YxI5IItUiXX6rFn_",
]);
const myObjectFiltered = Object.fromEntries(
Object.entries(myObject).filter(([key]) => mySet.has(key))
);
console.log(myObjectFiltered);Sure, just use .reduce to assign to a new object:
const addGroupMembers = Object.entries(myObject).filter(entry =>
mySet.has(entry[0])).reduce((accum, [k, v]) => {
accum[k] = v;
return accum;
}, {});
The question is to me a bit confusing sorry, but I hope this can contribute :
Basically, in javascript, to directly change an existing object to remove an element, and not create an altered copy, you can use :
delete someObject[key]
it will change directly your Object, which will applies to everything which have it referenced.
as such :
const myObject = {
"-Lz8YxHiwp8QZW3TqAFn": {
"first": "Breanna",
"last": "Blah",
},
"-Lz8YxHqQXWoaGOFRLrO": {
"first": "Joshua",
"last": "Blah",
},
"-Lz8YxHsMItaaTVNyQRE": {
"first": "Joziah",
"last": "Blah",
},
"-Lz8YxHwuVBMWl0Go6C5": {
"first": "Lino",
"last": "Blah",
},
"-Lz8YxHy0S-QkDaE1PkX": {
"first": "Rebecca",
"last": "Blah",
},
"-Lz8YxI5IItUiXX6rFn_": {
"first": "Rosario",
"last": "Blah",
},
"-Lz8YxIB_YTBF8liL855": {
"first": "Alissa",
"last": "Blah",
}
}
const mySet = [
"-Lz8YxMp-V0TfiwrkM49",
"-Lz8YxNQP2WkkO0qpkRJ",
"-Lz8YxHy0S-QkDaE1PkX",
"-MmFNgjyopU3E8z5g-zU",
"-Lz8YxLVi_uZp_RkcRIH",
"-MuEgimJOIbPw3GyKBJ3",
"-Lz8YxOFpVHx2xPI1mUu",
"-Lz8YxJ-_wuk8bmEyvGT",
"-Lz8YxKj5WXY1oNwylQ4",
"-Lz8YxN87U1YM6_fKgq1",
"-Lz8YxOI4qszJvZhrSde",
"-Lz8YxI5IItUiXX6rFn_",
]
for (const i in myObject)
if (!mySet.includes(i))
delete myObject[i];
console.log(myObject);
An example case. Sorry for changing the syntax but it looks weird, hope it helps.