Expo

Get Started
API Reference

Alert

Launches an alert dialog with the specified title and message.
Optionally provide a list of buttons. Tapping any button will fire the respective onPress callback and dismiss the alert. By default, the only button will be an 'OK' button.
This is an API that works both on Android and iOS and can show static alerts. Alert that prompts the user to enter some information is available on iOS only.

Example

iOSAndroid
iOS Alert ExampleAndroid Alert Example
import React, { useState } from 'react';
import { View, StyleSheet, Button, Alert } from 'react-native';

const App = () => {
  const createTwoButtonAlert = () =>
    Alert.alert('Alert Title', 'My Alert Msg', [
      {
        text: 'Cancel',
        onPress: () => console.log('Cancel Pressed'),
        style: 'cancel',
      },
      { text: 'OK', onPress: () => console.log('OK Pressed') },
    ]);

  const createThreeButtonAlert = () =>
    Alert.alert('Alert Title', 'My Alert Msg', [
      {
        text: 'Ask me later',
        onPress: () => console.log('Ask me later pressed'),
      },
      {
        text: 'Cancel',
        onPress: () => console.log('Cancel Pressed'),
        style: 'cancel',
      },
      { text: 'OK', onPress: () => console.log('OK Pressed') },
    ]);

  return (
    <View style={styles.container}>
      <Button title={'2-Button Alert'} onPress={createTwoButtonAlert} />
      <Button title={'3-Button Alert'} onPress={createThreeButtonAlert} />
    </View>
  );
};

const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'space-around',
    alignItems: 'center',
  },
});

export default App;

On iOS you can specify any number of buttons. Each button can optionally specify a style, available options are represented by the AlertButtonStyle enum.

On Android at most three buttons can be specified. Android has a concept of a neutral, negative and a positive button:
  • If you specify one button, it will be the 'positive' one (such as 'OK')
  • Two buttons mean 'negative', 'positive' (such as 'Cancel', 'OK')
  • Three buttons mean 'neutral', 'negative', 'positive' (such as 'Later', 'Cancel', 'OK')
Alerts on Android can be dismissed by tapping outside of the alert box. It is disabled by default and can be enabled by providing an optional Options parameter with the cancelable property set to true i.e.
{ cancelable: true }.
The cancel event can be handled by providing an onDismiss callback property inside the options parameter.

import React from 'react';
import { View, StyleSheet, Button, Alert } from 'react-native';

const showAlert = () =>
  Alert.alert(
    'Alert Title',
    'My Alert Msg',
    [
      {
        text: 'Cancel',
        onPress: () => Alert.alert('Cancel Pressed'),
        style: 'cancel',
      },
    ],
    {
      cancelable: true,
      onDismiss: () =>
        Alert.alert('This alert was dismissed by tapping outside of the alert dialog.'),
    }
  );

const App = () => (
  <View style={styles.container}>
    <Button title="Show alert" onPress={showAlert} />
  </View>
);

const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
  },
});

export default App;

static alert(title, message?, buttons?, options?)
Parameters:
NameTypeDescription
title (Required)stringThe dialog's title. Passing null or empty string will hide the title.
messagestringAn optional message that appears below the dialog's title.
buttonsButtonsAn optional array containing buttons configuration.
options (Android)OptionsAn optional Alert configuration for the Android.

static prompt(title, message?, callbackOrButtons?, type?, defaultValue?, keyboardType?)
Create and display a prompt to enter some text in form of Alert.
Parameters:
NameTypeDescription
title (Required)stringThe dialog's title.
messagestringAn optional message that appears above the text input.
callbackOrButtonsfunction
Buttons
If passed a function, it will be called with the prompt's value
(text: string) => void, when the user taps 'OK'.
If passed an array, buttons will be configured based on the array content.
typeAlertTypeThis configures the text input.
defaultValuestringThe default text in text input.
keyboardTypestringThe keyboard type of first text field (if exists). One of TextInput keyboardTypes.

An iOS Alert button style.
Type
enum
Constants:
ValueDescription
'default'Default button style.
'cancel'Cancel button style.
'destructive'Destructive button style.

An iOS Alert type.
Type
enum
Constants:
ValueDescription
'default'Default alert with no inputs
'plain-text'Plain text input alert
'secure-text'Secure text input alert
'login-password'Login and password alert

Array of objects containg Alert buttons configuration.
Type
array of objects
Objects properties:
NameTypeDescription
textstringButton label.
onPressfunctionCallback function when button is pressed.
style (iOS)AlertButtonStyleButton style, on Android this property will be ignored.

Type
object
Properties:
NameTypeDescription
cancelablebooleanDefines if alert can be dismissed by tapping outside of the alert box.
onDismissfunctionCallback function fired when alert has been dismissed.