Throttling for Improved Performance and User Experience (Live Playground)

Throttling is a technique used to limit the rate at which a function is executed, particularly when it comes to events that are triggered frequently, like scrolling, resizing, or typing in an input field. By executing the function at a fixed interval, you can improve the performance of your web application and provide a better user experience.

Why use throttling?

Throttling is useful in situations where a function is called repeatedly in a short period of time, which can cause performance issues or an unresponsive user interface. By executing the function at a fixed interval, you can control the rate at which it is called, improving the overall performance of your application.

How to implement throttling

To implement throttling, you can use a simple JavaScript function that wraps your original function and adds a delay before executing it.

Here's an example of a throttle function:

function throttle(func, limit) {
  let lastFunc;
  let lastRan;
  return function (...args) {
    const context = this;
    if (!lastRan) {
      func.apply(context, args);
      lastRan = Date.now();
    } else {
      clearTimeout(lastFunc);
      lastFunc = setTimeout(() => {
        if (Date.now() - lastRan >= limit) {
          func.apply(context, args);
          lastRan = Date.now();
        }
      }, limit - (Date.now() - lastRan));
    }
  };
}

In this example, the throttle function takes two arguments: the function you want to throttle (func) and the time interval between executions (limit). The function returns a new function that, when called, either executes the original function immediately or sets a timeout to execute it later, depending on the time that has passed since the last execution.

Here's how you can use the throttle function in your code:

const updateLayout = () => {
  console.log('Updating layout...');
};

const throttledUpdateLayout = throttle(updateLayout, 250);

window.addEventListener('resize', throttledUpdateLayout);

In this example, we create a simple updateLayout function that logs a message when it's called. We then use the throttle function to create a throttledUpdateLayout function, which we use as the event listener for the resize event. This ensures that the updateLayout function is called at a fixed interval when the window is resized, improving the performance of the application.

Live Playground, Try it Yourself

Conclusion

By using throttling, you can optimize the performance of your web applications and provide a better user experience, especially when dealing with events that can be triggered frequently.