How To Use React Native Timer (Code Examples)

React Native Timer is a great way to manage time-based events in your app. In this tutorial, you will learn how to use React Native Timer and all of its features.

What is a Timer?

A timer is a special type of clock that is used to count down from a given time interval. It can be used to measure the duration of an event, or to track how long it takes for a user to complete a task. Timers are commonly used in interactive applications such as games, to ensure the user is not taking too long to complete a task.

When To Use a Timer in React Native?

React Native Timer can be used in any React Native project that requires a timer. Some common use cases are:

• Creating a timer to track the duration of an event
• Counting down from a given time interval
• Tracking how long it takes for a user to complete a task
• Creating a game timer

Setting up React Native Environment

Before you can start using React Native Timer, you need to set up your React Native environment. To do this, you will need to install the latest version of React Native CLI.

Once you have installed the React Native CLI, you can create a new React Native project by running the following command:

react-native init MyTimerApp

This will create a new React Native project called MyTimerApp. Now you are ready to start using React Native Timer in your project.

Building a Simple Timer App in React Native

Now that you have set up your React Native environment, you can start building a simple timer app. To do this, you will need to create a new React Native component called Timer.

The Timer component will be responsible for rendering the timer display and handling user interactions. To get started, open the MyTimerApp project in your code editor and create a new file called Timer.js.

In the Timer.js file, import the StyleSheet, Text, and View components from the React Native library:

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

Next, define the Timer component and add the render() method:

export default class Timer extends React.Component {
  render() {
    return (
      <View>
        <Text>Timer</Text>
      </View>
    );
  }
}

The Timer component is now ready to be used in your React Native app. To do this, open the App.js file and import the Timer component:

import React from 'react';
import Timer from './Timer';

Now, update the render() method to render the Timer component:

render() {
  return (
    <View>
      <Timer />
    </View>
  );
}

The Timer component is now rendered in your React Native app. Now you can start adding the timer functionality. To do this, you will need to add state to the Timer component.

At the top of the Timer.js file, define a state object and set the time property to 0:

state = {
  time: 0,
};

Next, add the startTimer() and stopTimer() methods to the Timer component. The startTimer() method will be responsible for starting the timer and the stopTimer() method will be responsible for stopping the timer:

startTimer = () => {
  // Start the timer
};

stopTimer = () => {
  // Stop the timer
};

To start the timer, you will need to use the setInterval() method. The setInterval() method will call a function at regular intervals.

In the startTimer() method, call the setInterval() method and pass in a callback function to update the time state property:

startTimer = () => {
  this.interval = setInterval(() => {
    this.setState(state => ({
      time: state.time + 1,
    }));
  }, 1000);
};

The setInterval() method is called every second and the time state property is incremented by 1.

To stop the timer, you will need to use the clearInterval() method. In the stopTimer() method, call the clearInterval() method and pass in the interval variable:

stopTimer = () => {
  clearInterval(this.interval);
};

Now you can add the timer display to the render() method of the Timer component. To do this, use the Text component to render the time state property:

render() {
  return (
    <View>
      <Text>{this.state.time}</Text>
    </View>
  );
}

The timer display is now rendered in the Timer component. Now you can add the start and stop buttons. To do this, create two new TouchableOpacity components and add the onPress props to call the startTimer() and stopTimer() methods:

<TouchableOpacity onPress={this.startTimer}>
  <Text>Start</Text>
</TouchableOpacity>

<TouchableOpacity onPress={this.stopTimer}>
  <Text>Stop</Text>
</TouchableOpacity>

The Timer component is now complete. When you run the React Native app, you should see the timer display and the start and stop buttons.

Conclusion

In this tutorial, you learned how to use React Native Timer in your React Native app. You learned how to set up the React Native environment, create a Timer component, and add the timer functionality.

You now have the skills to create a timer app in React Native. Try experimenting with different time intervals and see what you can create!