How can I resolve this warning ? "Encountered Two Children with the same key, `.$1/.$2`"-CodePudding

I am making a select input in my react native App using import "react-native-form-select-picker", And the code is working fine still it is giving me a warning as "Encountered Two Children with the same key, `.$1/.$2". So how can I fix this Issue Can someone please help? Below is my lines of code:

import React, { useState } from 'react';
import { View, Text, StyleSheet, TouchableOpacity, } from 'react-native';
import SelectPicker from 'react-native-form-select-picker';

const options = ["Aadhar Card", "Bank Passbook", "Driving Licence", "Pan Card"];

// create a component
const UpdateDocument = ({ navigation }) => {

    const [selected, setSelected] = useState();

    return (
        <View style={styles.container}>
            <View style={styles.docBox}>
                <SelectPicker
                    placeholder="Select document to Update"
                    style={styles.selectBox}
                    onValueChange={(value) => {
                        // Do anything you want with the value. 
                        // For example, save in state.
                        setSelected(value);
                    }}
                    selected={selected}
                >

                    {Object.values(options).map((val, index) => (
                        <SelectPicker.Item label={val} value={val} key={} />
                    ))}

                </SelectPicker>
            </View>
        </View>
    );
};

// define your styles
const styles = StyleSheet.create({
    container: {
        flex: 1,
        backgroundColor: '#fff',
    },
    docBox: {
        paddingVertical: 10,
        paddingHorizontal: 10,
        borderBottomColor: '#aaa',
        borderBottomWidth: 1,
    },
    selectBox: { borderColor: '#555', borderWidth: 1, borderRadius: 4, }
});

//make this component available to the app
export default UpdateDocument;

CodePudding user response：

Keys help React identify which items have changed, are added, or are removed. That's why React wants you to add unique keys to every element whenever you iterate over a list of objects to render multiple JSX elements. If you omit keys, items do not get stable identities within the list, and React will yell at you in the console: Warning: Each child in a list should have a unique “key” prop.

So if each of your option in the options lst are unique which would only make sense then you can just do this.

{Object.values(options).map((val, index) => (
                        <SelectPicker.Item label={val} value={val} key={val} />
                    ))}