React-Native useCallback hook problems

Question

I am trying to alert the user when they press submit as to what option they chose based on the CheckBox .

The problem I am having is that when I check the checkbox of today and tomorrow the actual state outside the handleSubmit function is true however in the handleSubmit function both today and tomorrow are false and I don't know how to get the actual state to render in useCallBack hook.

Please can someone see where I am going wrong and assist me. Thank You!!!

import React, { useEffect, useState, useCallback } from 'react'
import { CheckBox } from 'react-native-elements'
import { Alert } from 'react-native'

const Choose = (props) => {
    const [today, setToday] = useState(false)
    const [tommorow, setTommorow] = useState(false)

    useEffect(() => {
        props.navigation.setParams({ handleSubmit: handleSubmit })
    }, [handleSubmit])

    console.log(`today is ${today}`) // this works and is changed by the check box
    const handleSubmit = useCallback(() => {
        if (today == true){
            console.log(`today is ${today}`) // today from outise this function is never true
            
            Alert.alert('You selected today')
        }else if (tommorow == true){
            Alert.alert('You selected tommorow')
        }
    }, [today, tommorow])

    return (
        <View>
            <CheckBox
                checked={world}
                onPress={() => setToday(!today)}
                title='Today'
            />
            <CheckBox
                onPress={() => setTommorow(!tommorow)}
                title='Tommorow'
            />
        </View>
    )
}
export default ChooseToAdd

Choose.navigationOptions = () => {
    const submit = navigationData.navigation.getParam('handleSubmit')
    return {
        headerRight: () =>
            <TouchableOpacity onPress={submit}>
                <Text>Submit</Text>
            </TouchableOpacity>
    }
}

Answer 1

your useEffect which trigger on handleSubmit is defined before the definition of handleSubmit

Answer 2

1. You have to write useEffect hook after handleSubmit function

2. use toggleHandler function for both today & tomorrow

    setState(prev => !prev)

3. Use if statement for both case because you have checkbox not radio button, So there is chances of both check boxes is checked.