1var bills = [
2 {
3 "refNo": 17,
4 "billDate": "1-apr-2016",
5 "dueDate": "30-apr-2016",
6 "pendingAmount": 4500,
7 "overdueDays": 28
8 },
9 {
10 "refNo": 20,
11 "billDate": "15-apr-2016",
12 "dueDate": "3-may-2016",
13 "pendingAmount": 56550,
14 "overdueDays": 15
15 }
16 ];
17var res = bills.map(bill => bill.pendingAmount).reduce((acc, bill) => bill + acc);
18console.log(res)