Not able to use map function react-native - arrays

Question

I am new to react native and I am using Async storage to store objects and then parse, by storing them in favorites array. I am trying to map each element in array and display it.
I get this error: this.state.favorites.map is not a function.
I think it's a state error but as I'm new to these concepts, i don't know how to fix it. Please help.
import React, {Component} from 'react';
import {StyleSheet, Text, View, Image, FlatList, Button, AsyncStorage,
TouchableOpacity} from 'react-native';
import ajax from './ajax.js';
import PropTypes from 'prop-types';
import InspirationList from './InspirationList';
import FavoriteItem from './FavoriteItem';
import ProductItem from './ProductItem';
class Favorites extends Component{
state = {
favorites:[],
};
componentDidMount(){
this.showProduct();
}
async showProduct() {
let k=0;
AsyncStorage.getAllKeys()
.then(keys => AsyncStorage.multiGet(keys)
.then((result) => {
result.map(req => req.forEach((element) => {
k++;
if(element!=null && k%2==0){
this.setState({favorites: JSON.parse(element) });
console.log(this.state.favorites.nume);
}
}));
}));
};
render(){
return(
<View style='styles.fav'>
{this.state.favorites.map((fav)=>
<Text>{fav.nume}</Text>
)}
</View>
);
}
}
const styles = StyleSheet.create({
fav:{
backgroundColor:'#999',
flex:1,
width:'100%',
paddingTop:150,
}
});
export default Favorites;

Answer 1

On your showProduct function you are overriding what your state originally was. When assigning the JSON.parse(element) you are changing your state instead of having an array your are converting it into an object, that's why you are getting that error. map exists only on array-like.
So maybe you can do something like:
async showProduct() {
let k=0;
AsyncStorage.getAllKeys()
.then(keys => AsyncStorage.multiGet(keys)
.then((result) => {
result.map(req => {
let result = [];
req.forEach((element) => {
k++;
if(element!=null && k%2==0){
result.push(JSON.parse(element))
}
});
this.setState({favorites: result });}
);
}));
};