Javascript - Variable loose it's value after block

Question

Can somebody explain me how to solve this problem?

let konyvSzam=0;

   db.checkPeldanySzam(rentISBN,(konyv) => {
        konyvSzam=konyv.Peldanyszam;
    });

    console.log("Nr of books");
    console.log(konyvSzam);

The variable gets the value but after I check it doesn't work

That's not a block, it is a function, and it isn't losing its value after it, it just doesn't have the new value before that function gets called. — Quentin, May 03 '20 at 17:10

score 1 · Answer 1 · answered May 03 '20 at 17:11

1

Mostly our DB call works asynchrous in node js and JavaScript try to enclose db calls in promise or use async/await .

answered May 03 '20 at 17:11

Vivek Anand

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Can you give me a little example, I'm quite new in this. Thank you. – MrNobody May 03 '20 at 17:12

Javascript - Variable loose it's value after block

1 Answers1