Throttling is a technique used to control how many times we allow a function to be executed over time. When a JavaScript function is said to be throttled with a wait time of X milliseconds, it can only be invoked at most once every X milliseconds. The callback is invoked immediately and cannot be invoked again for the rest of the wait duration.

Implement throttle(func, wait) so that func can run at most once every wait milliseconds. The first call should invoke func immediately. Calls made during the throttling window should be ignored. When func runs, it should receive the call's arguments and preserve this.

Arguments

1. func (Function): The callback to throttle.
2. wait (number): The number of milliseconds in each throttling window.

Returns

(Function): Returns the throttled function.

Examples

let i = 0;
function increment() {
  i++;
}
const throttledIncrement = throttle(increment, 100);

// t = 0: Call throttledIncrement(). i is now 1.
throttledIncrement(); // i = 1

// t = 50: Call throttledIncrement() again.
//  i is still 1 because 100ms have not passed.
throttledIncrement(); // i = 1

// t = 101: Call throttledIncrement() again. i is now 2.
//  i can be incremented because it has been more than 100ms
//  since the last throttledIncrement() call at t = 0.
throttledIncrement(); // i = 2

Follow up

• Throttle with cancel and leading/trailing options.

Reading

• Throttle on Lodash Documentation