What is throttle

Throttling is a technique used in software development to control the rate at which a function is executed. This is particularly useful when dealing with events that can fire frequently, such as window resizing, scrolling, or keystrokes, to ensure that the function is not called too often, potentially causing performance issues.

How Throttling Works:

1. Frequent Events: In many web applications, certain events like scrolling, resizing, or typing can trigger numerous times in a very short period. Without control, this can lead to performance degradation or unnecessary processing.

2. Controlled Execution: Throttling limits the number of times a function can be executed over a specified period, ensuring the function runs at regular intervals regardless of how many times the event is triggered.

3. Throttling Process:

   • Fixed Time Intervals: Throttling ensures that a function can only be executed once within a defined time interval.
   • Ignore Excess Calls: Any calls to the function that occur within the throttled time period are ignored until the next interval starts.

Demo

Last click at -- not yet :<

Throttle update date 2 seconds -- not yet :<

Implementation

Here is a simple implementation of throttle in Javascript.

function throttle(callback, delayMilliseconds) {
  let timer = null;
  return function (...args) {
    if (timer) return;
    callback(...args);
    timer = setTimeout(() => {
      timer = null;
    }, delayMilliseconds);
  };
}

In this example:

• lastCall keeps track of the last time the callback was executed.
• The returned function calculates the current time (now) and compares it with lastCall.
• If the difference between now and lastCall is greater than or equal to the specified delayMilliseconds, the callback is executed, and lastCall is updated.

Importance of Throttling:

• Enhances Performance: By reducing the frequency of function calls, throttling helps to prevent performance bottlenecks and ensures smoother user interactions.
• Efficient Resource Use: Throttling conserves resources by preventing unnecessary function executions, which can be particularly important in resource-constrained environments or when performing expensive operations.
• Improves User Experience: Ensures that functions responding to high-frequency events (like scrolling or resizing) are executed in a controlled and predictable manner, resulting in a more responsive and stable application.

Throttling is an essential technique in web development, particularly when dealing with event-driven programming, to maintain optimal performance and user experience.