I am trying to access the previous state when i click this button but it does not seem to be working

Question

I am trying to access the previous state but it keeps returning the same number please help

      let scrollUp = () => {


        setItems(prevnumberOfItems => prevnumberOfItems + 1000);
        alert(numberOfItems)
        window.scrollBy(0, -numberOfItems);
        alert(numberOfItems);
        setCounter(counter + 1);
        console.log(counter);
      };

I keep getting the same number back in setItems and setBeforeItems

     setItems(productRowLength * 530 + mobile);
      setbeforeItems(prevnumberOfItems => prevnumberOfItems + 1000);

Possible duplicate of [useState set method not reflecting change immediately](https://stackoverflow.com/questions/54069253/usestate-set-method-not-reflecting-change-immediately/54069332#54069332) — Shubham Khatri, Aug 16 '19 at 05:23

score 0 · Answer 1 · answered Aug 16 '19 at 06:04

setState offers a callback function so if we do something like this -:

this.setState({someValue: 10});
console.log(this.state.someValue); //can't expect it to be 10, can be previous value too because setState is async.

but if we do something like this -:

this.setState({someValue: 10}, () => console.log(this.state.someValue)); // definitely will be 10.

Syntax for setState -:

this.setState({ //properties and value },//callback function to be executed);

I am trying to access the previous state when i click this button but it does not seem to be working

1 Answers1