Benchmark: IIFE vs regular code v2

Tests:

IIFE
let sum = 0; for (let i = 0; i < 100; i++) { const a = (() => 4)(); sum += a; }
regular code
let sum = 0; for (let i = 0; i < 100; i++) { const a = 4; sum += a; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
IIFE
regular code

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36

Browser/OS: Chrome 120 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
IIFE	10104186.0 Ops/sec
regular code	20795454.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested.

**Benchmark Definition**

The benchmark is comparing two approaches: Immediately Invoked Function Expression (IIFE) and regular code. The benchmark definition provides the JavaScript code that will be executed in each approach.

In both cases, a variable `sum` is initialized to 0, and then a loop runs 100 times, adding either the result of an IIFE or a direct constant value to `sum`.

**Options Compared**

Two options are being compared:

1. **IIFE**: An Immediately Invoked Function Expression (IIFE) is used to wrap the code inside a function that's executed immediately after it's defined.
2. **Regular Code**: The code is executed directly without any additional wrapping.

**Pros and Cons of Each Approach**

* **IIFE**:
	+ Pros: Can provide encapsulation, scope isolation, and can be useful for creating single-use functions.
	+ Cons: May incur a runtime overhead due to the function call, even if the function body is empty or optimized away by the JavaScript engine.
* **Regular Code**:
	+ Pros: Often results in faster execution since there's no unnecessary function call overhead.
	+ Cons: Lacks encapsulation and scope isolation, making it harder to manage complex logic.

**Library and Special JS Feature**

There are no libraries being used in this benchmark. However, the use of IIFE is an example of a special JavaScript feature called a "closure." A closure is a function that has access to its own scope and can capture variables from that scope, even when the outer function has returned.

**Other Considerations**

The benchmark results are likely influenced by various factors, such as:

* **JavaScript Engine Optimization**: Modern JavaScript engines like V8 (used in Chrome) often perform optimization techniques like constant folding, dead code elimination, and tree shaking. These optimizations can affect the performance difference between IIFE and regular code.
* **Cache Performance**: The browser's cache may also impact the benchmark results, especially if the same code is executed multiple times with different inputs.

**Alternatives**

If you're interested in exploring alternative benchmarks or variations on this one, here are a few ideas:

* Compare IIFE vs. arrow functions
* Examine the performance of different scope types (e.g., `let`, `var`, `const`)
* Investigate the impact of code splitting or module loading on performance

Related benchmarks:

IIFE vs regular code v2 (version: 0)

Check if IIFE have a negative runtime impact or if they are optimized away

Comparing performance of: IIFE vs regular code

Created: 2 years ago by: Guest

Jump to the latest result

IIFE

regular code

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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