Create a timer in React with Start, Pause and Reset feature

Hello guys, i came across this task during my interview with a great company so i thought to share it with you all. The task is to create a countdown timer in React with Start, Pause and Reset features, so let's start building it -

// Import the useState hook from React for managing state
import { useState } from "react";

// Import the CSS file for styling
import "./styles.css";

// Define the main App component
export default function App() {
  // Initialize state variables for timer and timeInterval
  const [timer, setTimer] = useState(0);
  const [timeInterval, setTimeInterval] = useState(null);

  // Function to start the timer
  const startTimer = () => {
    // Use setInterval to update the timer every 1000 milliseconds (1 second)
    setTimeInterval(setInterval(() => {
      // Update the timer by incrementing the previous value by 1
      setTimer((prev) => prev + 1);
    }, 1000));
  }

  // Function to pause the timer
  const pauseTimer = () => {
    // Clear the interval to stop the timer from updating
    clearInterval(timeInterval);
  }

  // Function to reset the timer
  const resetTimer = () => {
    // Reset the timer value to 0
    setTimer(0);
    // Clear the interval to stop the timer
    clearInterval(timeInterval);
  }

  // Render the timer and buttons in the component
  return (
    <div className="App">
      <h3>Timer: {timer}</h3>
      <div className="btn-wrapper">
        {/* Button to start the timer */}
        <button onClick={startTimer}>Start</button>
        {/* Button to pause the timer */}
        <button onClick={pauseTimer}>Pause</button>
        {/* Button to reset the timer */}
        <button onClick={resetTimer}>Reset</button>
      </div>
    </div>
  );
}

This is the complete code, i hope you found it informative and you can extend it to next level by setting a timer and decreasing it until 0. See you soon in the next post 😊

Comments

[Mursal Furqan Kumbhar]

Thank you so much for sharing this amazing code. However, I would suggest that before sharing the complete code, you should divide the code into smaller pieces and components and explain them a little bit as well, so that it is understandable by beginners as well.

Cool piece by the way. Keep sharing knowledge.

[Indrakant Mishra]

Thanks mate, sure will do that way from next time