validation-box/doc/save/mobile.mdx

The only validation library - with flexible regex - you need.

---

title: Mobile App's
description: Validation Box works seamlessly with most JS/TS frameworks.
---


Validation Box can be used in mobile applications to validate user inputs, login forms, and phone numbers in React Native and Expo projects.

Validation Box is compatible with mobile frameworks for validating form inputs.

## React Native

React Native allows developers to create cross-platform mobile apps using JavaScript. Below, we validate usernames in a mobile form.

```tsx
import React, { useState } from "react";
import { TextInput, Button, Text, View } from "react-native";
import { validateUsername } from "validation-box";

export default function UsernameValidator() {
  const [username, setUsername] = useState("");
  const [error, setError] = useState("");

  const handleValidation = () => {
    const isValid = validateUsername(username, { min: 5 });
    setError(isValid ? "Valid Username" : "Invalid Username");
  };

  return (
    <View style={{ padding: 20 }}>
      <TextInput
        style={{ borderBottomWidth: 1, marginBottom: 10 }}
        placeholder="Enter Username"
        value={username}
        onChangeText={setUsername}
      />
      <Button title="Validate" onPress={handleValidation} />
      {error ? <Text style={{ color: "red" }}>{error}</Text> : null}
    </View>
  );
}
```

Exploring new mobile integrations? If you successfully integrate Validation Box into another mobile framework, we’d love to see your contribution!