How to change the state of a const on React with useState?

Question

I'm doing a jokenpô game with react and I need to make a scoreboard that start with the state of the player and the computer with 0 and changes when some of them wins the game I've made a function

 const handlePlacar = () =>{
    if(victory === 'You'){
      setPlacarPlayer(placarPlayer ++)
    }
    else if(victory === 'Computer'){
      setPlacarComputer(placarComputer ++)
    }
  }

and I'm calling this function as a prop in the component placar in App.js

      <Divs>
       <Placar computer={placarComputer} player={placarPlayer} handlePlacar={handlePlacar}/>
      </Divs>

the component Placar code

import React from 'react';
import {Table, TableHead, TableRow, TableCell, TableContainer, TableBody} from '@material-ui/core';

const Placar = (props) =>{


    return(
      
        <TableContainer>
        <Table>
          <TableHead>Placar</TableHead>
          <TableRow>
            <TableCell>Player</TableCell>
            <TableCell>Computer</TableCell>
          </TableRow>
          <TableBody>
            <TableRow>
              <TableCell>{props.player}</TableCell>
              <TableCell>{props.computer}</TableCell>
            </TableRow>
          </TableBody>
        </Table>
      </TableContainer>
    )
}

export default Placar

But the state isn't changing. I tried it with useEffect but It didn't work too.

Answer 1

Problem is that new value of state depends on previous state value. So you can update call setPlacarComputer method with callback.

const [count, setCount] = useState(0);


setCount(previousCount => previousCount + 1);