How to get id from json react-native-material-dropdown - react-native

Question

I have used react-native-material-dropdown in my react native project. I am getting a data from API.
I am sorry, my English is bad.
fetch('xxxx.json', {
method: 'POST',
headers: {
'Accept': 'application/json',
'Content-Type': 'application/json',
}
}).then((response) => response.json())
.then((responseJson) => {
var count = Object.keys(responseJson.cities).length;
for(var i=0;i<count;i++){
//console.warn(responseJson.cities[i].name) // I need to add
//these names to dropdown
this.state.drop_down_data.push({ value: responseJson.cities[i].name,id:responseJson.cities[i].id });
}
//this.setState({ drop_down_data });
})
.catch((error) => {
console.error(error);
});
and Dropdown code
<Dropdown
label='City'
data={this.state.drop_down_data}
onChangeText={this.onCityChange.bind(this)}
/>
and Change method issue is here
onCityChange(val,ind,data){ fetch('xxxx/'+ cityid +'/towns.json', {
method: 'POST',
headers: {
'Accept': 'application/json',
'Content-Type': 'application/json',
}
}).then((response) => response.json())
.then((responseJson) => {
this.setState({drop_down_data2: []});
var count = Object.keys(responseJson.towns).length;
for(var i=0;i<count;i++){
//console.warn(responseJson.towns[i].name) // I need to add
//these names to dropdown
//
this.state.drop_down_data2.push({ value: responseJson.towns[i].name,id:responseJson.towns[i].id });
}
//this.setState({ drop_down_data });
})
.catch((error) => {
console.error(error);
});
}
in here i want to city id.value is coming but id not coming or i dont know get to id.
if i can get id, i can a post request for town.
how i can do this?
and some json data
{
"id": 1,
"name": "Adana",
"alpha_2_code": "TR-01"
},
{
"id": 2,
"name": "Adıyaman",
"alpha_2_code": "TR-02"
},

Answer 1

onChangeText Method have 3 parameters (value, index, data)
data = Complete Array
index = Current Item index selected
You can get id by this code
onChangeText = (value, index, data) => {
const cityId = data[index].id;
console.log("cityId", cityId);
};
Complete Sample Code
import React, { Component } from "react";
import { Dropdown } from "react-native-material-dropdown";
const data = [
{
value: "City1",
id: 1
},
{
value: "City2",
id: 2
},
{
value: "City3",
id: 3
}
];
export default class Example extends Component {
onChangeText = (value, index, data) => {
const cityId = data[index].id;
console.log("cityId", cityId);
};
render() {
return (
<Dropdown
label="Favorite Fruit"
data={data}
style={{ marginTop: 50 }}
onChangeText={this.onChangeText}
/>
);
}
}