ReactNativePicker.js

import React from 'react';
import { View, Text, Picker, Platform } from 'react-native';

class MyPicker extends React.Component {
  state = {
    system: ''
  };

  render() {
    return (
      <View style={{ justifyContent: 'center', alignItems: 'center', flex: 1 }}>
        <Text>React Native Picker{' '}{Platform.select({ android: 'Android', ios: 'IOS' })}</Text>
        <Picker
          selectedValue={this.state.system}
          style={{ height: 50, width: 100 }}
          onValueChange={itemValue => this.setState({ system: itemValue })}
          itemstyle={{ width: 100 }}
        >
          <Picker.Item label="IOS" value="IOS" />
          <Picker.Item label="Android" value="Android" />
        </Picker>
      </View>
    );
  }
}

export default MyPicker;

lines 5-26, please indent :D @Karniej

line 12, it does not look aesthetic - it could be a one-line string

please apply the formatting to this file - you can choose the extension when creating a gist file