Map data structure in strict mode

Question

I am using strict mode for the following code. Trying to assign an object value from a Map. It is granted that the value I am getting from the Map isn't undefined but strict mode giving the following error Type A[]|undefined isn't assignable to type A[]. How can I pass this compiler issue?

let key = "foo"
leaderboardRecords: A[] = [];
leaderboardRecordsbyRegion: Map<string, A[]> = new Map<string, A[]>();
if (!leaderboardRecordsbyRegion.has(key)) {
        leaderboardRecordsbyRegion.set(key, fetchData());
    }
leaderboardRecords = leaderboardRecordsbyRegion.get(key);

There is highly likely chance that the return type of function fetchData() would be A[]|undefined. So error says that types are not matching. Simple — DecPK
– DecPK, Commented Oct 9, 2022 at 5:30
You should add minimal reproducible code, so that people can understand your problem clearly. — DecPK
– DecPK, Commented Oct 9, 2022 at 5:33
Use the Non-null assertion operator, leaderboardRecords = leaderboardRecordsbyRegion.get(key)!; — kikon
– kikon, Commented Oct 9, 2022 at 5:44
@PhilopateerNabil can you add your full code where this problem is reproducible — DecPK
– DecPK, Commented Oct 9, 2022 at 6:26

Philopateer Nabil · Accepted Answer · 2022-10-09 06:13:47Z

0

This is how I solved it in the end. I added or empty array to pass the compiler.

leaderboardRecords = leaderboardRecordsbyRegion.get(key) || [];

answered Oct 9, 2022 at 6:13

Philopateer Nabil

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