React native page keeps crashing, I can't see why - reactjs

Question

I'm making a react native app on Expo, but the whole app crashes everytime I try to get into this one page. This is my first time using react native, and I'm still a beginner to react, but I can't see what's causing the issue. The error I'm getting is Warning: Functions are not valid as a React child. This may happen if you return a Component instead of <Component /> from render. Or maybe you meant to call this function rather than return it., but I can't see where
import { StyleSheet, Text, View, TouchableOpacity, ScrollView, TextInput } from 'react-native'
import React, { useState, useEffect } from 'react'
// import CartCard from '../Components/CartCard'
import ItemCard from '../Components/ItemCard'
const Cart = ({navigation}) => {
const [details, setDetails] = useState([])
useEffect(()=>{
getData()
}, [])
const getData = async() => {
try {
const getValues = await AsyncStorage.getItem('object')
if(getValues !== null){
console.log(JSON.parse(getValues))
setDetails(getValues)
// const objectValues = JSON.parse(getValues)
// setDetails(objectValues)
// getValues.forEach(object => {
// console.log("id:", object.id)
// setToyId(object.id)
// })
}
}catch(error){
console.log('getData didnt work')
}
}
const [cardholder, setCardholder] = useState('');
const [cardNumber, setCardNumber] = useState('');
const [expiryDate, setExpiryDate] = useState('');
const [cvc, setCvc] = useState('');
const [allItems, setAllItems] = useState(0);
const [total, setTotal] = useState(0)
const clearCart = () => {
console.log('cc')
}
const countAllItems = () => {
console.log('cai')
}
const countTotal = () => {
console.log('ct')
}
return (
<ScrollView style={{backgroundColor: 'white', height: '100%'}}>
<ItemCard />
<View>
<View style={styles.payment}>
<Text>Your Shopping Cart</Text>
<View>
<Text value={allItems} onChangeText={(value)=>{setAllItems(value)}}>Overall Items: {countAllItems}</Text>
<Text value={total} onChangeText={(value)=>{setTotal(value)}}>Total Price: ${countTotal}.00</Text>
</View>
</View>
<Text>Payment</Text>
<TextInput placeholder='Cardholder Name' style={styles.inputsLong} placeholderTextColor='black' value={cardholder} onChangeText={(value)=>setCardholder(value)}/>
<TextInput placeholder='Card Number' style={styles.inputsLong} placeholderTextColor='black' value={cardNumber} onChangeText={(value)=>setCardNumber(value)}/>
<View style={styles.shortForm}>
<TextInput placeholder='MM/YY' style={styles.inputsShort} placeholderTextColor='black' value={expiryDate} onChangeText={(value)=>setExpiryDate(value)} />
<TextInput placeholder='CVC' style={styles.inputsShort} placeholderTextColor='black' value={cvc} onChangeText={(value)=>setCvc(value)}/>
</View>
<View style={styles.buttonRow}>
<TouchableOpacity>
<Text style={styles.cancelButton} onPress={clearCart}>Cancel Order</Text>
</TouchableOpacity>
<TouchableOpacity>
<Text style={styles.orderButton} onPress={()=>navigation.navigate('ConfirmScreen')}>Place Order</Text>
</TouchableOpacity>
</View>
</View>
</ScrollView>
)
}
export default Cart
const styles = StyleSheet.create({ // styles })
ItemCard component doesn't take any parameters yet because I'm having problems storing data and passing data between pages, but this is what the component looks like in its current state:
import { StyleSheet, Text, View, ScrollView } from 'react-native'
import React from 'react'
const ItemCard = () => {
return (
<ScrollView>
<View style={styles.itemSection}>
<View style={styles.card}></View>
</View>
</ScrollView>
)
}
export default ItemCard
const styles = StyleSheet.create({ // styles })

Answer 1

For this warning
Warning: Functions are not valid as a React child. This may happen if you return a Component instead of from render. Or maybe you meant to call this function rather than return it.
you have to call the functions
eg. countTotal()
<Text value={total} onChangeText={(value)=>{setTotal(value)}}>Total Price: ${countTotal()}.00</Text>
if you are using onPress then like this
<Text style={styles.cancelButton} onPress={()=>clearCart()}>Cancel Order</Text>