Benchmark: lookup vs closure declaration

Tests:

create closure
let num = Math.random(); let elem = { click: (elem) => num * 2 };
create object lookup
function reusable_click_handler(elem) { return elem.num * 2; } let num = Math.random(); let elem = { num, click: reusable_click_handler };
click closure
let num = Math.random(); let elem = { click: (elem) => num * 2 }; elem.click(elem);
click object lookup
function reusable_click_handler(elem) { return elem.num * 2; } let num = Math.random(); let elem = { num, click: reusable_click_handler }; elem.click(elem)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
create closure
create object lookup
click closure
click object lookup

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:105.0) Gecko/20100101 Firefox/105.0

Browser/OS: Firefox 105 on Windows

View result in a separate tab

Test name	Executions per second
create closure	17681784.0 Ops/sec
create object lookup	920869504.0 Ops/sec
click closure	15450514.0 Ops/sec
click object lookup	815836288.0 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated one month ago):

LLMs can make mistakes. Check important info.

**What is tested:**
The provided JSON represents a benchmark test case that compares two approaches to create closures in JavaScript:

1. **Lookup approach**: This involves directly accessing a property of an object using the dot notation (`elem.click(elem)`).
2. **Closure creation approach**: This involves creating a new function that captures the value of a variable in its scope, and then assigns this function to a property of an object (`let num = Math.random(); let elem = { click: (elem) => num * 2 };`).

**Options comparison:**

*   **Lookup approach (create closure)**:
    *   Pros:
        *   Simpler code structure.
        *   Less memory usage, as there is no need to store the function.
    *   Cons:
        *   Can be slower due to the overhead of resolving the dot notation.
        *   May lead to unexpected behavior if not handled carefully (e.g., when using `undefined` or `null` values).
*   **Closure creation approach (click object lookup)**:
    *   Pros:
        *   More explicit and readable code structure.
        *   Can be faster due to the reduced overhead of resolving dot notation.
    *   Cons:
        *   Requires more memory, as a new function needs to be stored in memory.

**Other considerations:**

*   The benchmark test cases are designed to measure the execution speed of each approach. However, it's essential to note that the results may also depend on factors like code optimization, caching, and browser-specific optimizations.
*   In general, when creating closures in JavaScript, using the arrow function syntax (e.g., `() => { ... }`) can simplify the code and improve performance.

**Library usage:**
In this benchmark test case, there is no explicit library usage. However, the use of modern JavaScript features like arrow functions (`=>`) is implicitly relying on the browser's support for these features.

**Special JS feature or syntax:**
There is no specific JavaScript feature or syntax that requires special consideration in this benchmark test case. The code examples provided use standard JavaScript syntax and features, which are widely supported across most browsers and platforms.

**Alternative approaches:**

*   **Function expression approach**: Instead of using the arrow function syntax, you could define a regular function with the `function` keyword (e.g., `let elem = { click: function(elem) { return num * 2; } };`). This approach would be less readable and potentially slower due to the overhead of parsing and executing a function expression.
*   **Class-based approach**: You could create a class that encapsulates the closure, using the `class` keyword (e.g., `class ClosureExample extends Object { click(elem) { return elem.num * 2; } };`). This approach would introduce additional overhead due to class creation and method invocation.

Keep in mind that these alternative approaches are less common and may not be relevant for most use cases. The benchmark test case provided is designed to focus on the specific comparison between two closure creation approaches.

Related benchmarks:

lookup vs closure declaration (version: 0)

Comparing performance of: create closure vs create object lookup vs click closure vs click object lookup

Created: 2 years ago by: Guest

Jump to the latest result

create closure

create object lookup

click closure

click object lookup

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one month ago):