JavaScript：从键值数组中提取特定键的值并将它们存储在新数组中

Question

I have an' multidimensional key-value array like this:

 '[[ {"_time":"2022-01-03T00:00:00Z","_value":10.70140000000014,"ts":1641168000000}, {"_time":"2022-01-04T00:00:00Z","_value":13.002499999999767,"ts":1641254400000}, {"_time":"2022-01-05T00:00:00Z","_value":16.171700000000182,"ts":1641340800000}, {"_time":"2022-01-06T00:00:00Z","_value":17.48929999999981,"ts":1641427200000}, ]]'

and I need the values from each of them in a new variable in this way:

 [10.70140000000014,13.002499999999767,16.171700000000182,17.48929999999981]

I tried it with map but that do not match my needs:

 function getPreparedData(data) { if (data) { return data[0].map(elm => ({ a: elm._value })); } return []; };

How can I solve this?

Thanks

Frank

Answer 1

In your example, the function getPreparedData is returning array of objects. You actually want to return an array of values (where values are just the value of the _value property)

 const data = [[ {"_time":"2022-01-03T00:00:00Z","_value":10.70140000000014,"ts":1641168000000}, {"_time":"2022-01-04T00:00:00Z","_value":13.002499999999767,"ts":1641254400000}, {"_time":"2022-01-05T00:00:00Z","_value":16.171700000000182,"ts":1641340800000}, {"_time":"2022-01-06T00:00:00Z","_value":17.48929999999981,"ts":1641427200000}, ]]; function getPreparedData(data) { return data[0].map(elm => elm._value) }; const res = getPreparedData(data); console.log(res);