I currently have an array of items that looks a bit like this: I want to group the items by category lookup, with the slight problem that category lookup is potentially an array, such that Parent Item 2 would be listed twice (once in My Cat) and once in something else) I tried using https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/groupBy but it doesn't seem to be able to handle this?
[
{
"tool_id": "4-19de-454673d9-9ef5-4545",
"somekey" : "Parent Item 2"
"categoryLookup": [
{
"category_name": "New Item",
}
]
},
{
"tool_id": "be7ea707-19de-43d9-9ef1-d4a3ff79f77a",
"somekey" : "Parent Item"
"categoryLookup": [
{
"category_name": "My Cat",
},
{
"category_name": "Something Else",
}
]
}
]
The final result would look something like:
[
{
New Item: [
{...contains 4-19de-454673d9-9ef5-4545 }
],
My Cat: [
{...contains be7ea707-19de-43d9-9ef1-d4a3ff79f77a}
],
Something Else: [
{... contain be7ea707-19de-43d9-9ef1-d4a3ff79f77a}
]
}
]
You can iterate over the original array and create the final one:
var data = [{
"tool_id": "4-19de-454673d9-9ef5-4545",
"somekey": "Parent Item 2",
"categoryLookup": [{
"category_name": "New Item",
}]
},
{
"tool_id": "be7ea707-19de-43d9-9ef1-d4a3ff79f77a",
"somekey": "Parent Item",
"categoryLookup": [{
"category_name": "My Cat",
},
{
"category_name": "Something Else",
}
]
}
];
function groupByCategory(data) {
const res = {};
data.forEach(item => {
item.categoryLookup.forEach(category => {
const name = category.category_name;
res[name] ??= [];
res[name].push({
item: item.tool_id //or all the properties you want
});
});
});
return res;
}
console.log( groupByCategory(data) );