Implement throttle

Throttling is a technique that ensures that the function does not execute more than once in a specified time period.

This is useful for managing the performance of functions that could be triggered frequently.

You are required to implement throttle(fn, delay) decorator function.

Example

function throttle(fn, delay) {
  // Your implementation
}

const print = () => {
  console.log("print");
};

const fn = throttle(print, 1000);

// fn function will be called once in a second on window resize
window.addEventListener("resize", fn);

Solution

function throttle(fn, delay) {
  // Initialize a timer variable for managing the throttling
  let timer = null;

  // Return a new function that encapsulates the throttling logic
  return (...args) => {
    // if timer is already running, then just skip fn call
    if (timer) return;

    // Set a timer that delays the function execution
    timer = setTimeout(() => {
      // Execute the original function with the provided arguments
      fn(...args);

      // Clear the timer after the function executes and reset it to null
      clearTimeout(timer);
      timer = null;
    }, delay);
  };
}

const print = () => {
  console.log("print");
};

const fn = throttle(print, 1000);

// fn function will be called once in a second on window resize
window.addEventListener("resize", fn);