merge two javascripts array objects by adding index based on count

Question

I have the following object:

index;
@track cashList = [{Id: "",Index: index }];

My service outputs below object array:

result = [{Id:"100"},{Id:"101"},{Id:"102"}];

after merging with the result, cashList should look like

@track cashList = [{Id: "100",Index: 0 },{Id: "101",Index: 1 },{Id: "102",Index: 2 }];

cashList = result; //This one populating `Id` but not sure how to populate index

Any help would be appreciated.

Answer 1

you can map over an array and pass in the index so in the below ...item means you are keeping the existing object and adding in the index.

result.map((item,index) => ({
    ...item,
    index
}))