Im trying to create an multidimensional Object like this one:
{ A : {a1: {},a2:{}}, B: {b1:{},b2:{}}}
from an multidimensional array like this one:
let array1 = [
['A', 'a1'],
['A', 'a1'],
['A', 'a2'],
['B', 'b1'],
['B', 'b1'],
['B', 'b2'],
];
I'm trying this for some hours now and was also reading plenty of entrys here on stackoverflow, but nothing really fits this specific case.
What i did so far:
let array1 = [
['A', 'a1'],
['A', 'a1'],
['A', 'a2'],
['B', 'b1'],
['B', 'b1'],
['B', 'b2'],
];
let object1 = {};
array1.forEach(function (subArray) {
let level1 = subArray[0];
let level2 = subArray[1];
object1[[level1]] = { ...{ [level2]: {} } };
});
console.log('object: ', object1);
//desired output: object = { A : {a1: {},a2:{}}, B: {b1:{},b2:{}}}
//what I get: object = { A : {a2:{}}, B: {b2:{}}}So somehow in my code the entrys like {a1: {}} are getting overwritten in each iteration instead of adding a new entry.
Thanks a lot in advance.
You can use Array.reduce() along with some destructuring to get the required object output.
For each key, value pair in the original array, we add a property to the final object, (e.g. 'A'), then add a new object for each value in the array (e.g. 'a1', 'a2').
let array1 = [ ['A', 'a1'], ['A', 'a1'], ['A', 'a2'], ['B', 'b1'], ['B', 'b1'], ['B', 'b2'], ];
let output = array1.reduce((acc, [k,v]) => {
acc[k] = { ...(acc[k] || {}), [v]: {} };
return acc;
}, {})
console.log(output).as-console-wrapper { max-height: 100% !important; top: 0; }One could also do this in a one-liner, but I think it's a lot harder to read (and understand):
let array1 = [ ['A', 'a1'], ['A', 'a1'], ['A', 'a2'], ['B', 'b1'], ['B', 'b1'], ['B', 'b2'], ];
let output = array1.reduce((acc, [k,v]) => ({ ...acc, [k]: { ...(acc[k] || {}), [v]: {} } }), {});
console.log(output).as-console-wrapper { max-height: 100% !important; top: 0; }Keep previous properties using ...object1[[level1]]:
let array1 = [
['A', 'a1'],
['A', 'a1'],
['A', 'a2'],
['B', 'b1'],
['B', 'b1'],
['B', 'b2'],
];
let object1 = {};
array1.forEach(function (subArray) {
let level1 = subArray[0];
let level2 = subArray[1];
object1[[level1]] = {
...object1[[level1]], // Keep previous properties
...{ [level2]: {} } // Add new
};
});
console.log('object: ', object1);