I have a list of objects that contain an array as one of the values like so:
const obj_arr = [
{'key': ['value-1', 'value-2', 'value-3', 'value-2', 'value-3']},
{'key': ['value-3', 'value-1', 'value-2', 'value-1', 'value-3']},
{'key': ['value-2', 'value-1', 'value-4', 'value-3', 'value-5']}
];
How do I take this list of values and map only the unique items to an array?
so far I have been able to do this:
const obj_arr = [{
'key': ['value-1', 'value-2', 'value-3', 'value-2', 'value-3']
},
{
'key': ['value-3', 'value-1', 'value-2', 'value-1', 'value-3']
},
{
'key': ['value-2', 'value-1', 'value-4', 'value-3', 'value-5']
}
];
let unique_arr = [...new Set(obj_arr.map(record => record['key']))];
console.log(unique_arr);
/*
let unique_arr2 = [...new Set(obj_arr.flatMap(record => record['key']))];
console.log('using guidance from Barmar: ', unique_arr2);
*/.as-console-wrapper { max-height: 100% !important; top: 0 }but this only gives me back each unique array like this:
unique_arr = [
['value-1', 'value-2', 'value-3', 'value-2', 'value-3'],
['value-3', 'value-1', 'value-2', 'value-1', 'value-3'],
['value-2', 'value-1', 'value-4', 'value-3', 'value-5']
]
what I actually need is this:
unique_arr = ['value-1', 'value-2', 'value-3', 'value-4', 'value-5']
I don't know if this is the result you're looking for here is a solution with reduce
let uniqueArrReduce = [...new Set(obj_arr.reduce((acc, el) => [...acc, ...el.key], []) )]
with map and flat
let uniqueArrMapFlat = [...new Set(obj_arr.map(el => el.key).flat())]
You could map the values of the objects and get a flat array for the constructor.
const
array = [{ key: ['value-1', 'value-2', 'value-3', 'value-2', 'value-3'] }, { key: ['value-3', 'value-1', 'value-2', 'value-1', 'value-3'] }, { key: ['value-2', 'value-1', 'value-4', 'value-3', 'value-5'] }],
unique = [...new Set(array.map(Object.values).flat(Infinity))];
console.log(unique);