Last value of array when object available

Question

I am trying to find the last value of GDPAnn from the array Annual. The code below works fine. But if GDPAnn is not available in the last value, it returns undefined. For example, I want value 10251000 of GDPAnn from array Annual2.

var Annual = [{"Date":1998,"Value":4.5,"GDPAnn":9062800},{"Date":1999,"Value":4.8,"GDPAnn":9631200},{"Date":2000,"Value":4.1,"GDPAnn":10251000},{"Date":2001,"Value":1,"GDPAnn":10581900}]

x = Annual.map((o) => o.GDPAnn).pop();
console.log(x);

var Annual2 = [{"Date":1998,"Value":4.5,"GDPAnn":9062800},{"Date":1999,"Value":4.8,"GDPAnn":9631200},{"Date":2000,"Value":4.1,"GDPAnn":10251000},{"Date":2001,"Value":1}]

y = Annual2.map((o) => o.GDPAnn).pop();
console.log(y);

Filter the array to only include items with a key GDPAnn before running your .map() — StudioTime
– StudioTime, Commented Mar 21, 2022 at 10:07

StudioTime · Accepted Answer · 2022-03-21 10:09:50Z

2

Please see comment in code below - use .filter()

var Annual = [{"Date":1998,"Value":4.5,"GDPAnn":9062800},{"Date":1999,"Value":4.8,"GDPAnn":9631200},{"Date":2000,"Value":4.1,"GDPAnn":10251000},{"Date":2001,"Value":1,"GDPAnn":10581900}]

x = Annual.map((o) => o.GDPAnn).pop();
console.log(x);

var Annual2 = [{"Date":1998,"Value":4.5,"GDPAnn":9062800},{"Date":1999,"Value":4.8,"GDPAnn":9631200},{"Date":2000,"Value":4.1,"GDPAnn":10251000},{"Date":2001,"Value":1}]

// Adding filter here to only include items with the GDPAnn key
y = Annual2.filter((o) => o.GDPAnn).map((o) => o.GDPAnn).pop();
console.log(y);

answered Mar 21, 2022 at 10:09

StudioTime

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Comments

Peterrabbit · Accepted Answer · 2022-03-21 10:10:13Z

1

This could be a simple workaround

var Annual = [{"Date":1998,"Value":4.5,"GDPAnn":9062800},{"Date":1999,"Value":4.8,"GDPAnn":9631200},{"Date":2000,"Value":4.1,"GDPAnn":10251000},{"Date":2001,"Value":1,"GDPAnn":10581900}]

x = Annual.map((o) => o.GDPAnn).pop();
console.log(x);

var Annual2 = [{"Date":1998,"Value":4.5,"GDPAnn":9062800},{"Date":1999,"Value":4.8,"GDPAnn":9631200},{"Date":2000,"Value":4.1,"GDPAnn":10251000},{"Date":2001,"Value":1}]

y = Annual2.filter(o=> o.GDPAnn).map((o) => o.GDPAnn).pop();
console.log(y);

answered Mar 21, 2022 at 10:10

Peterrabbit

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Bane2000 · Accepted Answer · 2022-03-21 10:12:55Z

0

let y = Annual2.reduce((prev, curr) => curr.GDPAnn ? curr : prev).GDPAnn

answered Mar 21, 2022 at 10:12

Bane2000

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