How to Implement Form Validation in React Native ?

React Native is a JavaScript framework for cross-platform mobile app development. Expo CLI simplifies React Native development with a streamlined process and helpful tools. In this article, we'll see how to implement form validation in react native.

Form validation ensures the validity of user input by checking against specific rules or constraints. In React Native, form validation involves validating input fields based on conditions or patterns, such as email or password requirements.

Prerequisites:

• Introduction to React Native
• Introduction React Native Components
• React Native State
• Expo CLI

Form validation ensures data integrity by preventing incorrect submissions. React Native allows easy validation using state management and custom functions.

Steps to Setup and Run React Native Project

Step 1: Set Up the Development Environment

To begin, ensure Expo CLI is installed on your system. If not, run this command in your terminal to install it globally:

npm install -g expo-cli

Step 2: Create React Native Application With Expo CLI

Create a new React Native project using Expo CLI by running this command in your terminal:

expo init form-vlidation-app 

Step 3: ​Navigate to the project directory by using this command:

cd form-vlidation-app 

Example: In this example, React Native component that implements a form with name, email, and password inputs. It performs validation on the inputs and displays error messages if any validation rules are not met. The form submission is handled when the form is valid.

Step 4: Open the App.js file and write down the following code in App.js.

Step 5: To run the react native application, open the Terminal and enter the command listed below. 

npx expo start

To run on Android:

npx react-native run-android

To run on Ios:

npx react-native run-ios

Output: