Benchmark: AddEventListener vs direct v2

Tests:

Add
const element = document.createElement('div'); element.addEventListener('click', () => console.log(''));
Direct
const element = document.createElement('div'); element.onclick = () => console.log('');

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Add
Direct

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:135.0) Gecko/20100101 Firefox/135.0

Browser/OS: Firefox 135 on Windows

View result in a separate tab

Test name	Executions per second
Add	1131598.5 Ops/sec
Direct	749353.4 Ops/sec

Autogenerated LLM Summary (model gpt-4o-mini, generated 5 months ago):

LLMs can make mistakes. Check important info.

The benchmark titled "AddEventListener vs direct v2" compares two different methods for setting up event handlers in JavaScript, specifically a click event on a DOM element. The two approaches being tested are:

1. **Using `addEventListener`**: This method is part of the DOM API and allows developers to register event listeners on DOM elements. It enables the attachment of multiple event handlers for the same event without overwriting existing handlers.

```javascript
    const element = document.createElement('div');
    element.addEventListener('click', () => console.log(''));
    ```

2. **Using the `onclick` property**: This is an older, more straightforward method of assigning an event handler directly to a DOM element. Setting the `onclick` property will override any previously assigned click handlers.

```javascript
    const element = document.createElement('div');
    element.onclick = () => console.log('');
    ```

### Comparison of Approaches

#### **Pros and Cons**

1. **`addEventListener`**
   - **Pros**:
     - Supports multiple event listeners of the same type. You can add the same event type multiple times without losing previous handlers.
     - Provides additional options such as useCapture and once, giving more control over event propagation and handler invocation.
   - **Cons**:
     - Slightly more verbose and may involve a small overhead compared to directly assigning the onclick property.

2. **`onclick`**
   - **Pros**:
     - Simpler and more straightforward syntax for single event handler assignments; easier to understand for simple cases.
     - Minimal performance overhead when dealing with single handlers.
   - **Cons**:
     - Limits to one handler per event type, as each assignment replaces the previous one.
     - Less flexibility regarding event handling configurations (like event propagation control).

### Benchmark Results

The benchmark results demonstrate the performance differences between the two methods when executing the click event handling:

- **Direct (using `onclick`)**:
  - Executions per second: **2,977,684.25**
  
- **Add (using `addEventListener`)**:
  - Executions per second: **2,800,691.50**

This indicates that the direct assignment (onclick) outperforms using addEventListener in this specific benchmark scenario. However, the difference in performance is marginal and may vary based on the context of use, such as the complexity of the attached functions or the number of event listeners.

### Other Considerations

When selecting which event-handler approach to use, developers should consider the context of the application:

- For applications that require handling multiple event listeners or more complex event management, `addEventListener` is preferable despite its slight overhead.
- For simple interactions where only one handler is needed and performance is critical, using the `onclick` property could be more efficient.

### Alternatives

Besides `addEventListener` and `onclick`, there are other ways to manage events in JavaScript:

- **jQuery Events**: A popular library that provides a simpler API for event handling and works across different browsers.
- **Event Delegation**: Attaching a single event listener to a parent element rather than multiple listeners on child elements. This is useful for managing events on dynamically added elements.
- **Custom Events**: Utilizing the `CustomEvent` constructor to create and dispatch events for custom behaviors, allowing for custom event handling strategies.

Each method comes with its own trade-offs, and the choice largely depends on the specific use case and project requirements.

Related benchmarks:

AddEventListener vs direct v2 (version: 1)

Comparing performance of: Add vs Direct

Created: 5 months ago by: Guest

Jump to the latest result

Add

Direct

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gpt-4o-mini, generated 5 months ago):