Cannot access props sent from toggle in react native

Question

I am rendering this list like so

const roomsAttached = this.state.rooms_attached.map((item, index) => (
<View key={index}>
    <Text>{index}</Text>
    <Switch
    thumbColor='#eee'
    onValueChange={(value, index) => this.losToggle(value, index)}
    value={item.room_attached_los}
    />
</View>
))

I simply cannot access the index from the list item, I have always used a similar syntax and it worked out the box now all I am getting is undefined.

losToggle (los, index) {
    console.log('index :', index)
    console.log('LOS: ' + los)
}

Can please someone assist? I also tried item , same issue

Answer 1

Change the passed callback function definition in onValueChange prop, to this, will works:

onValueChange={value => this.losToggle(value, index)}