Multidimensional array of an unknown size in JavaScript
Really struggling to get my head around this...
I'm trying to sort items from an array into another array, but categorised. My code is currently working, but the trouble is that I need to know the size of the "sort" array. At the moment, there are four entries, which works with "data". The first two data.cat are compared to n, and their IDs are pushed into sort[0]. When two do not match, 1 is added to c. The code then loops through again, pushing the new matches into sort[1], etc, etc.
var data = [
{"cat": 0, "id":"AAAA"},
{"cat": 0, "id":"BBBB"},
{"cat": 1, "id":"CCCC"},
{"cat": 1, "id":"DDDD"},
{"cat": 1, "id":"EEEE"},
{"cat": 1, "id":"FFFF"}, //pseudodata
{"cat": 1, "id":"GGGG"},
{"cat": 2, "id":"HHHH"},
{"cat": 2, "id":"IIII"},
{"cat": 2, "id":"JJJJ"},
{"cat": 3, "id":"KKKK"}
];
var sort = [, , , ,]
function sortDates(){
var n = 0;
for (var i = 0; i < data.length; i++){
if (data[i].cat == n){
console.log("Category " + n +" entry: " + data[i].id);
sort[n].push(data[i].id);
} else {
console.log("Entry " + data[i].id + " does not match. Moving to next category...");
n++;
i--;
}
}
}
This all works okay, but if I add more to the data array (such as {"cat": 4, "id":"LLLL"}), the program crashes with "sort[n] is not a function". This is because there are only four available items in the sort array.
So I'm just wondering, is there any way to get around this? If the data array is always changing size, and more entries/categories are added, do I have to keep resizing the sort array manually?
javascript arrays loops multidimensional-array 2d
asked Nov 25 '18 at 19:20
default-LAdefault-LA
3517
add a comment |
Really struggling to get my head around this...
I'm trying to sort items from an array into another array, but categorised. My code is currently working, but the trouble is that I need to know the size of the "sort" array. At the moment, there are four entries, which works with "data". The first two data.cat are compared to n, and their IDs are pushed into sort[0]. When two do not match, 1 is added to c. The code then loops through again, pushing the new matches into sort[1], etc, etc.
var data = [
{"cat": 0, "id":"AAAA"},
{"cat": 0, "id":"BBBB"},
{"cat": 1, "id":"CCCC"},
{"cat": 1, "id":"DDDD"},
{"cat": 1, "id":"EEEE"},
{"cat": 1, "id":"FFFF"}, //pseudodata
{"cat": 1, "id":"GGGG"},
{"cat": 2, "id":"HHHH"},
{"cat": 2, "id":"IIII"},
{"cat": 2, "id":"JJJJ"},
{"cat": 3, "id":"KKKK"}
];
var sort = [, , , ,]
function sortDates(){
var n = 0;
for (var i = 0; i < data.length; i++){
if (data[i].cat == n){
console.log("Category " + n +" entry: " + data[i].id);
sort[n].push(data[i].id);
} else {
console.log("Entry " + data[i].id + " does not match. Moving to next category...");
n++;
i--;
}
}
}
This all works okay, but if I add more to the data array (such as {"cat": 4, "id":"LLLL"}), the program crashes with "sort[n] is not a function". This is because there are only four available items in the sort array.
So I'm just wondering, is there any way to get around this? If the data array is always changing size, and more entries/categories are added, do I have to keep resizing the sort array manually?
javascript arrays loops multidimensional-array 2d
asked Nov 25 '18 at 19:20
default-LAdefault-LA
3517
add a comment |
Really struggling to get my head around this...
I'm trying to sort items from an array into another array, but categorised. My code is currently working, but the trouble is that I need to know the size of the "sort" array. At the moment, there are four entries, which works with "data". The first two data.cat are compared to n, and their IDs are pushed into sort[0]. When two do not match, 1 is added to c. The code then loops through again, pushing the new matches into sort[1], etc, etc.
var data = [
{"cat": 0, "id":"AAAA"},
{"cat": 0, "id":"BBBB"},
{"cat": 1, "id":"CCCC"},
{"cat": 1, "id":"DDDD"},
{"cat": 1, "id":"EEEE"},
{"cat": 1, "id":"FFFF"}, //pseudodata
{"cat": 1, "id":"GGGG"},
{"cat": 2, "id":"HHHH"},
{"cat": 2, "id":"IIII"},
{"cat": 2, "id":"JJJJ"},
{"cat": 3, "id":"KKKK"}
];
var sort = [, , , ,]
function sortDates(){
var n = 0;
for (var i = 0; i < data.length; i++){
if (data[i].cat == n){
console.log("Category " + n +" entry: " + data[i].id);
sort[n].push(data[i].id);
} else {
console.log("Entry " + data[i].id + " does not match. Moving to next category...");
n++;
i--;
}
}
}
This all works okay, but if I add more to the data array (such as {"cat": 4, "id":"LLLL"}), the program crashes with "sort[n] is not a function". This is because there are only four available items in the sort array.
So I'm just wondering, is there any way to get around this? If the data array is always changing size, and more entries/categories are added, do I have to keep resizing the sort array manually?
javascript arrays loops multidimensional-array 2d
asked Nov 25 '18 at 19:20
default-LAdefault-LA
3517
Really struggling to get my head around this...
I'm trying to sort items from an array into another array, but categorised. My code is currently working, but the trouble is that I need to know the size of the "sort" array. At the moment, there are four entries, which works with "data". The first two data.cat are compared to n, and their IDs are pushed into sort[0]. When two do not match, 1 is added to c. The code then loops through again, pushing the new matches into sort[1], etc, etc.
var data = [
{"cat": 0, "id":"AAAA"},
{"cat": 0, "id":"BBBB"},
{"cat": 1, "id":"CCCC"},
{"cat": 1, "id":"DDDD"},
{"cat": 1, "id":"EEEE"},
{"cat": 1, "id":"FFFF"}, //pseudodata
{"cat": 1, "id":"GGGG"},
{"cat": 2, "id":"HHHH"},
{"cat": 2, "id":"IIII"},
{"cat": 2, "id":"JJJJ"},
{"cat": 3, "id":"KKKK"}
];
var sort = [, , , ,]
function sortDates(){
var n = 0;
for (var i = 0; i < data.length; i++){
if (data[i].cat == n){
console.log("Category " + n +" entry: " + data[i].id);
sort[n].push(data[i].id);
} else {
console.log("Entry " + data[i].id + " does not match. Moving to next category...");
n++;
i--;
}
}
}
This all works okay, but if I add more to the data array (such as {"cat": 4, "id":"LLLL"}), the program crashes with "sort[n] is not a function". This is because there are only four available items in the sort array.
So I'm just wondering, is there any way to get around this? If the data array is always changing size, and more entries/categories are added, do I have to keep resizing the sort array manually?
javascript arrays loops multidimensional-array 2d
javascript arrays loops multidimensional-array 2d
asked Nov 25 '18 at 19:20
default-LAdefault-LA
3517
asked Nov 25 '18 at 19:20
default-LAdefault-LA
3517
asked Nov 25 '18 at 19:20
default-LAdefault-LA
3517
asked Nov 25 '18 at 19:20
default-LAdefault-LA
3517
asked Nov 25 '18 at 19:20
default-LAdefault-LA
3517
3517
add a comment |
add a comment |
2 Answers
2
active
oldest
votes
You could use a default check of the array with a logical OR || and assign an empty array if the item is not set.
sort[n] = sort[n] || ;
sort[n].push(data[i].id);
BTW, you could use cat directly without iterating sort array for getting the right index.
function sortDates() {
var i, sort = ;
for (i = 0; i < data.length; i++) {
sort[data[i].cat] = sort[data[i].cat] || ;
sort[data[i].cat].push(data[i].id);
}
return sort;
}
var data = [{ cat: 0, id: "AAAA" }, { cat: 0, id: "BBBB" }, { cat: 1, id: "CCCC" }, { cat: 1, id: "DDDD" }, { cat: 1, id: "EEEE" }, { cat: 1, id: "FFFF" }, { cat: 1, id: "GGGG" }, { cat: 2, id: "HHHH" }, { cat: 2, id: "IIII" }, { cat: 2, id: "JJJJ" }, { cat: 3, id: "KKKK" }],
result = sortDates(data);
console.log(result);.as-console-wrapper { max-height: 100% !important; top: 0; }answered Nov 25 '18 at 19:23
Nina ScholzNina Scholz
191k15104176
Absolutely perfect - thank you! I knew there was a more efficient way to do this... so the line:sort[data[i].cat] = sort[data[i].cat] || ;Is this basically saying, pushdata[i]tosort[data[i].cat], or ifsort[data[i].catdoesn't exist, use the logic OR, which pushes it into a new item insort?
– default-LA
Nov 25 '18 at 20:38
right first the check and if not a truthy value, like an array, then assign an array and later push the new value.
– Nina Scholz
Nov 25 '18 at 20:41
add a comment |
Another way you can achieve this with ES6 in a more concise manner is to use Array.reduce and inside Array.sort via String.localeCompare:
var data = [{ "cat": 0, "id": "BBBB" }, { "cat": 0, "id": "AAAA" }, { "cat": 1, "id": "CCCC" }, { "cat": 1, "id": "DDDD" }, { "cat": 1, "id": "EEEE" }, { "cat": 1, "id": "FFFF" }, { "cat": 1, "id": "GGGG" }, { "cat": 2, "id": "HHHH" }, { "cat": 2, "id": "IIII" }, { "cat": 2, "id": "JJJJ" }, { "cat": 3, "id": "KKKK" } ]
const result = Object.values(data.reduce((r,c) => {
r[c.cat] = [...r[c.cat] || , c.id].sort((a,b) => a.localeCompare(b))
return r
}, {}))
console.log(result)String.localeCompare has various options in terms of how to compare (like dealing with numbers in the strings, case sensitivity etc)
The idea is to use the Array.reduce is to group the entries in an object and then just use Object.values to get the desired output (milti-dimentional array).
answered Nov 25 '18 at 20:46
AkrionAkrion
9,53011224
add a comment |
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2 Answers
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active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
You could use a default check of the array with a logical OR || and assign an empty array if the item is not set.
sort[n] = sort[n] || ;
sort[n].push(data[i].id);
BTW, you could use cat directly without iterating sort array for getting the right index.
function sortDates() {
var i, sort = ;
for (i = 0; i < data.length; i++) {
sort[data[i].cat] = sort[data[i].cat] || ;
sort[data[i].cat].push(data[i].id);
}
return sort;
}
var data = [{ cat: 0, id: "AAAA" }, { cat: 0, id: "BBBB" }, { cat: 1, id: "CCCC" }, { cat: 1, id: "DDDD" }, { cat: 1, id: "EEEE" }, { cat: 1, id: "FFFF" }, { cat: 1, id: "GGGG" }, { cat: 2, id: "HHHH" }, { cat: 2, id: "IIII" }, { cat: 2, id: "JJJJ" }, { cat: 3, id: "KKKK" }],
result = sortDates(data);
console.log(result);.as-console-wrapper { max-height: 100% !important; top: 0; }answered Nov 25 '18 at 19:23
Nina ScholzNina Scholz
191k15104176
Absolutely perfect - thank you! I knew there was a more efficient way to do this... so the line:sort[data[i].cat] = sort[data[i].cat] || ;Is this basically saying, pushdata[i]tosort[data[i].cat], or ifsort[data[i].catdoesn't exist, use the logic OR, which pushes it into a new item insort?
– default-LA
Nov 25 '18 at 20:38
right first the check and if not a truthy value, like an array, then assign an array and later push the new value.
– Nina Scholz
Nov 25 '18 at 20:41
add a comment |
You could use a default check of the array with a logical OR || and assign an empty array if the item is not set.
sort[n] = sort[n] || ;
sort[n].push(data[i].id);
BTW, you could use cat directly without iterating sort array for getting the right index.
function sortDates() {
var i, sort = ;
for (i = 0; i < data.length; i++) {
sort[data[i].cat] = sort[data[i].cat] || ;
sort[data[i].cat].push(data[i].id);
}
return sort;
}
var data = [{ cat: 0, id: "AAAA" }, { cat: 0, id: "BBBB" }, { cat: 1, id: "CCCC" }, { cat: 1, id: "DDDD" }, { cat: 1, id: "EEEE" }, { cat: 1, id: "FFFF" }, { cat: 1, id: "GGGG" }, { cat: 2, id: "HHHH" }, { cat: 2, id: "IIII" }, { cat: 2, id: "JJJJ" }, { cat: 3, id: "KKKK" }],
result = sortDates(data);
console.log(result);.as-console-wrapper { max-height: 100% !important; top: 0; }answered Nov 25 '18 at 19:23
Nina ScholzNina Scholz
191k15104176
Absolutely perfect - thank you! I knew there was a more efficient way to do this... so the line:sort[data[i].cat] = sort[data[i].cat] || ;Is this basically saying, pushdata[i]tosort[data[i].cat], or ifsort[data[i].catdoesn't exist, use the logic OR, which pushes it into a new item insort?
– default-LA
Nov 25 '18 at 20:38
right first the check and if not a truthy value, like an array, then assign an array and later push the new value.
– Nina Scholz
Nov 25 '18 at 20:41
add a comment |
You could use a default check of the array with a logical OR || and assign an empty array if the item is not set.
sort[n] = sort[n] || ;
sort[n].push(data[i].id);
BTW, you could use cat directly without iterating sort array for getting the right index.
function sortDates() {
var i, sort = ;
for (i = 0; i < data.length; i++) {
sort[data[i].cat] = sort[data[i].cat] || ;
sort[data[i].cat].push(data[i].id);
}
return sort;
}
var data = [{ cat: 0, id: "AAAA" }, { cat: 0, id: "BBBB" }, { cat: 1, id: "CCCC" }, { cat: 1, id: "DDDD" }, { cat: 1, id: "EEEE" }, { cat: 1, id: "FFFF" }, { cat: 1, id: "GGGG" }, { cat: 2, id: "HHHH" }, { cat: 2, id: "IIII" }, { cat: 2, id: "JJJJ" }, { cat: 3, id: "KKKK" }],
result = sortDates(data);
console.log(result);.as-console-wrapper { max-height: 100% !important; top: 0; }answered Nov 25 '18 at 19:23
Nina ScholzNina Scholz
191k15104176
You could use a default check of the array with a logical OR || and assign an empty array if the item is not set.
sort[n] = sort[n] || ;
sort[n].push(data[i].id);
BTW, you could use cat directly without iterating sort array for getting the right index.
function sortDates() {
var i, sort = ;
for (i = 0; i < data.length; i++) {
sort[data[i].cat] = sort[data[i].cat] || ;
sort[data[i].cat].push(data[i].id);
}
return sort;
}
var data = [{ cat: 0, id: "AAAA" }, { cat: 0, id: "BBBB" }, { cat: 1, id: "CCCC" }, { cat: 1, id: "DDDD" }, { cat: 1, id: "EEEE" }, { cat: 1, id: "FFFF" }, { cat: 1, id: "GGGG" }, { cat: 2, id: "HHHH" }, { cat: 2, id: "IIII" }, { cat: 2, id: "JJJJ" }, { cat: 3, id: "KKKK" }],
result = sortDates(data);
console.log(result);.as-console-wrapper { max-height: 100% !important; top: 0; }function sortDates() {
var i, sort = ;
for (i = 0; i < data.length; i++) {
sort[data[i].cat] = sort[data[i].cat] || ;
sort[data[i].cat].push(data[i].id);
}
return sort;
}
var data = [{ cat: 0, id: "AAAA" }, { cat: 0, id: "BBBB" }, { cat: 1, id: "CCCC" }, { cat: 1, id: "DDDD" }, { cat: 1, id: "EEEE" }, { cat: 1, id: "FFFF" }, { cat: 1, id: "GGGG" }, { cat: 2, id: "HHHH" }, { cat: 2, id: "IIII" }, { cat: 2, id: "JJJJ" }, { cat: 3, id: "KKKK" }],
result = sortDates(data);
console.log(result);.as-console-wrapper { max-height: 100% !important; top: 0; }function sortDates() {
var i, sort = ;
for (i = 0; i < data.length; i++) {
sort[data[i].cat] = sort[data[i].cat] || ;
sort[data[i].cat].push(data[i].id);
}
return sort;
}
var data = [{ cat: 0, id: "AAAA" }, { cat: 0, id: "BBBB" }, { cat: 1, id: "CCCC" }, { cat: 1, id: "DDDD" }, { cat: 1, id: "EEEE" }, { cat: 1, id: "FFFF" }, { cat: 1, id: "GGGG" }, { cat: 2, id: "HHHH" }, { cat: 2, id: "IIII" }, { cat: 2, id: "JJJJ" }, { cat: 3, id: "KKKK" }],
result = sortDates(data);
console.log(result);.as-console-wrapper { max-height: 100% !important; top: 0; }answered Nov 25 '18 at 19:23
Nina ScholzNina Scholz
191k15104176
edited Nov 25 '18 at 19:28
answered Nov 25 '18 at 19:23
Nina ScholzNina Scholz
191k15104176
answered Nov 25 '18 at 19:23
Nina ScholzNina Scholz
191k15104176
answered Nov 25 '18 at 19:23
Nina ScholzNina Scholz
191k15104176
191k15104176
Absolutely perfect - thank you! I knew there was a more efficient way to do this... so the line:sort[data[i].cat] = sort[data[i].cat] || ;Is this basically saying, pushdata[i]tosort[data[i].cat], or ifsort[data[i].catdoesn't exist, use the logic OR, which pushes it into a new item insort?
– default-LA
Nov 25 '18 at 20:38
right first the check and if not a truthy value, like an array, then assign an array and later push the new value.
– Nina Scholz
Nov 25 '18 at 20:41
add a comment |
Absolutely perfect - thank you! I knew there was a more efficient way to do this... so the line:sort[data[i].cat] = sort[data[i].cat] || ;Is this basically saying, pushdata[i]tosort[data[i].cat], or ifsort[data[i].catdoesn't exist, use the logic OR, which pushes it into a new item insort?
– default-LA
Nov 25 '18 at 20:38
right first the check and if not a truthy value, like an array, then assign an array and later push the new value.
– Nina Scholz
Nov 25 '18 at 20:41
Absolutely perfect - thank you! I knew there was a more efficient way to do this... so the line:
sort[data[i].cat] = sort[data[i].cat] || ; Is this basically saying, push data[i] to sort[data[i].cat], or if sort[data[i].cat doesn't exist, use the logic OR, which pushes it into a new item in sort?– default-LA
Nov 25 '18 at 20:38
Absolutely perfect - thank you! I knew there was a more efficient way to do this... so the line:
sort[data[i].cat] = sort[data[i].cat] || ; Is this basically saying, push data[i] to sort[data[i].cat], or if sort[data[i].cat doesn't exist, use the logic OR, which pushes it into a new item in sort?– default-LA
Nov 25 '18 at 20:38
right first the check and if not a truthy value, like an array, then assign an array and later push the new value.
– Nina Scholz
Nov 25 '18 at 20:41
right first the check and if not a truthy value, like an array, then assign an array and later push the new value.
– Nina Scholz
Nov 25 '18 at 20:41
add a comment |
Another way you can achieve this with ES6 in a more concise manner is to use Array.reduce and inside Array.sort via String.localeCompare:
var data = [{ "cat": 0, "id": "BBBB" }, { "cat": 0, "id": "AAAA" }, { "cat": 1, "id": "CCCC" }, { "cat": 1, "id": "DDDD" }, { "cat": 1, "id": "EEEE" }, { "cat": 1, "id": "FFFF" }, { "cat": 1, "id": "GGGG" }, { "cat": 2, "id": "HHHH" }, { "cat": 2, "id": "IIII" }, { "cat": 2, "id": "JJJJ" }, { "cat": 3, "id": "KKKK" } ]
const result = Object.values(data.reduce((r,c) => {
r[c.cat] = [...r[c.cat] || , c.id].sort((a,b) => a.localeCompare(b))
return r
}, {}))
console.log(result)String.localeCompare has various options in terms of how to compare (like dealing with numbers in the strings, case sensitivity etc)
The idea is to use the Array.reduce is to group the entries in an object and then just use Object.values to get the desired output (milti-dimentional array).
answered Nov 25 '18 at 20:46
AkrionAkrion
9,53011224
add a comment |
Another way you can achieve this with ES6 in a more concise manner is to use Array.reduce and inside Array.sort via String.localeCompare:
var data = [{ "cat": 0, "id": "BBBB" }, { "cat": 0, "id": "AAAA" }, { "cat": 1, "id": "CCCC" }, { "cat": 1, "id": "DDDD" }, { "cat": 1, "id": "EEEE" }, { "cat": 1, "id": "FFFF" }, { "cat": 1, "id": "GGGG" }, { "cat": 2, "id": "HHHH" }, { "cat": 2, "id": "IIII" }, { "cat": 2, "id": "JJJJ" }, { "cat": 3, "id": "KKKK" } ]
const result = Object.values(data.reduce((r,c) => {
r[c.cat] = [...r[c.cat] || , c.id].sort((a,b) => a.localeCompare(b))
return r
}, {}))
console.log(result)String.localeCompare has various options in terms of how to compare (like dealing with numbers in the strings, case sensitivity etc)
The idea is to use the Array.reduce is to group the entries in an object and then just use Object.values to get the desired output (milti-dimentional array).
answered Nov 25 '18 at 20:46
AkrionAkrion
9,53011224
add a comment |
Another way you can achieve this with ES6 in a more concise manner is to use Array.reduce and inside Array.sort via String.localeCompare:
var data = [{ "cat": 0, "id": "BBBB" }, { "cat": 0, "id": "AAAA" }, { "cat": 1, "id": "CCCC" }, { "cat": 1, "id": "DDDD" }, { "cat": 1, "id": "EEEE" }, { "cat": 1, "id": "FFFF" }, { "cat": 1, "id": "GGGG" }, { "cat": 2, "id": "HHHH" }, { "cat": 2, "id": "IIII" }, { "cat": 2, "id": "JJJJ" }, { "cat": 3, "id": "KKKK" } ]
const result = Object.values(data.reduce((r,c) => {
r[c.cat] = [...r[c.cat] || , c.id].sort((a,b) => a.localeCompare(b))
return r
}, {}))
console.log(result)String.localeCompare has various options in terms of how to compare (like dealing with numbers in the strings, case sensitivity etc)
The idea is to use the Array.reduce is to group the entries in an object and then just use Object.values to get the desired output (milti-dimentional array).
answered Nov 25 '18 at 20:46
AkrionAkrion
9,53011224
Another way you can achieve this with ES6 in a more concise manner is to use Array.reduce and inside Array.sort via String.localeCompare:
var data = [{ "cat": 0, "id": "BBBB" }, { "cat": 0, "id": "AAAA" }, { "cat": 1, "id": "CCCC" }, { "cat": 1, "id": "DDDD" }, { "cat": 1, "id": "EEEE" }, { "cat": 1, "id": "FFFF" }, { "cat": 1, "id": "GGGG" }, { "cat": 2, "id": "HHHH" }, { "cat": 2, "id": "IIII" }, { "cat": 2, "id": "JJJJ" }, { "cat": 3, "id": "KKKK" } ]
const result = Object.values(data.reduce((r,c) => {
r[c.cat] = [...r[c.cat] || , c.id].sort((a,b) => a.localeCompare(b))
return r
}, {}))
console.log(result)String.localeCompare has various options in terms of how to compare (like dealing with numbers in the strings, case sensitivity etc)
The idea is to use the Array.reduce is to group the entries in an object and then just use Object.values to get the desired output (milti-dimentional array).
var data = [{ "cat": 0, "id": "BBBB" }, { "cat": 0, "id": "AAAA" }, { "cat": 1, "id": "CCCC" }, { "cat": 1, "id": "DDDD" }, { "cat": 1, "id": "EEEE" }, { "cat": 1, "id": "FFFF" }, { "cat": 1, "id": "GGGG" }, { "cat": 2, "id": "HHHH" }, { "cat": 2, "id": "IIII" }, { "cat": 2, "id": "JJJJ" }, { "cat": 3, "id": "KKKK" } ]
const result = Object.values(data.reduce((r,c) => {
r[c.cat] = [...r[c.cat] || , c.id].sort((a,b) => a.localeCompare(b))
return r
}, {}))
console.log(result)var data = [{ "cat": 0, "id": "BBBB" }, { "cat": 0, "id": "AAAA" }, { "cat": 1, "id": "CCCC" }, { "cat": 1, "id": "DDDD" }, { "cat": 1, "id": "EEEE" }, { "cat": 1, "id": "FFFF" }, { "cat": 1, "id": "GGGG" }, { "cat": 2, "id": "HHHH" }, { "cat": 2, "id": "IIII" }, { "cat": 2, "id": "JJJJ" }, { "cat": 3, "id": "KKKK" } ]
const result = Object.values(data.reduce((r,c) => {
r[c.cat] = [...r[c.cat] || , c.id].sort((a,b) => a.localeCompare(b))
return r
}, {}))
console.log(result)answered Nov 25 '18 at 20:46
AkrionAkrion
9,53011224
answered Nov 25 '18 at 20:46
AkrionAkrion
9,53011224
answered Nov 25 '18 at 20:46
AkrionAkrion
9,53011224
answered Nov 25 '18 at 20:46
AkrionAkrion
9,53011224
9,53011224
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