Return values from an array based on dynamic array of keys

Question

I have an array of keys and I want to iterate of them and return their corresponding values.

Generally, I know, I can just do a object.key_name or object[key_name] but I have a dynamic array and will populate with different keys.

Data:

data = [{hello: 'abc', asd: '123', fgh: '345' }, 
{hello: 'sdf', asd: '456', fgh: 'df' }, 
{hello: 'ty', asd: '789', fgh: '345675' },
{hello: 'qwe', asd: '123', fgh: '987' }]

array format: arr = ['asd', 'fgh']

I am trying to do: let x = data.map(o => arr.map(strs => o[strs]));

Result:

["123", "345"]
["456", "df"]
["789", "345675"]
["123", "987"]

Is there any way for me to get:

["123", "456", "789", "123"]  <= array for asd
["345", "df", "345675", "987"] <= array for fgh

Answer 1

Change the order of your map calls - first iterate the format array, and then extract the values from the data :

 const data = [{"hello":"abc","asd":"123","fgh":"345"},{"hello":"sdf","asd":"456","fgh":"df"},{"hello":"ty","asd":"789","fgh":"345675"},{"hello":"qwe","asd":"123","fgh":"987"}] const format = ['asd', 'fgh'] const result = format.map(f => data.map(o => o[f])) console.log(result)

Answer 2

You where almost there: You just need to start with the array of the keys:

arr.map(key => data.map(o => o[key]));