why is there an error when selecting data in the picker?

   <Picker
      selectedValue={data}
      onValueChange={itemValue => setdata(itemValue)}>
      <Picker.Item label="Pilih Bencana" value="" />
      {data &&
        data?.map((item, key) => {
          return (
            <Picker.Item label={item.bencana} value={item.ID} key={key} />
          );
        })}
    </Picker>

The code above can display data, but when the data is selected an error like this occurs undefined is not a function (near '...data.map...') where to fix?

>Solution :

That because you setdata with onValueChange props, and the itemValue are not an array anymore.

.map work only with array

https://developer.mozilla.org/fr/docs/Web/JavaScript/Reference/Global_Objects/Array/map

You have to use another React.useState to keep item value save ‘itemValue’ to use it and show there