Extract JSON object properties into new array with Javascript

Question

I have a over 100+ JSON objects with this format:

{
"grants":[
{
 "grant":0,
 "ID": "EP/E027261/1",
 "Title": "Semiconductor Research at the Materials-Device Interface",
 "PIID": "6674",
 "Scheme": "Platform Grants",
 "StartDate": "01/05/2007",
 "EndDate": "31/10/2012",
 "Value": "800579"
}, ... more grants

I want to be able to grab EndDate and Value into a new array. Like the following output.

"extractedGrants":[
{
 "EndDate": "31/10/2012",
 "Value": "800579"
}, ... more extracted objects with EndDate and Value properties.

I believe the correct approach is to use array.map(function (a) {}); but I cannot get the code right inside the function.

Thanks.

Answer 1

You could use a destruction of the object and a new object for the result array.

var object = { grants: [{ grant: 0, ID: "EP/E027261/1", Title: "Semiconductor Research at the Materials-Device Interface", PIID: "6674", Scheme: "Platform Grants", StartDate: "01/05/2007", EndDate: "31/10/2012", Value: "800579" }] },
 result = object.grants.map(({ EndDate, Value }) => ({ EndDate, Value }));
console.log(result);

ES5

var object = { grants: [{ grant: 0, ID: "EP/E027261/1", Title: "Semiconductor Research at the Materials-Device Interface", PIID: "6674", Scheme: "Platform Grants", StartDate: "01/05/2007", EndDate: "31/10/2012", Value: "800579" }] },
 result = object.grants.map(function (a) {
 return { EndDate: a.EndDate, Value: a.Value };
 });
console.log(result);