Benchmark: let or without let (2)

Script Preparation code:

let i = 0;

Tests:

with let
for(let x = 0; x < 1000; x++) { let j = 0 j++; }
without let
for(let x = 0; x < 1000; x++) { i++; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
with let
without let

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 6 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.36

Browser/OS: Chrome 126 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
with let	2913982.2 Ops/sec
without let	252340.8 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark definition and test cases to understand what is being tested.

**Benchmark Definition**

The benchmark definition represents a JavaScript code snippet that defines a simple loop with an incrementing variable `j` or `i`. The purpose of this benchmark is to compare the performance of using the `let` keyword versus not using it in a simple loop.

**Script Preparation Code**

The script preparation code is used to initialize variables before running the benchmark. In this case, `let i = 0;` initializes variable `i` to 0 before the loop starts.

**Html Preparation Code**

There is no HTML preparation code provided for this benchmark, which means that the benchmark only runs in a JavaScript context and does not interact with any HTML elements.

**Test Cases**

The test cases are two separate benchmarks:

1. **"with let"`**: This benchmark uses the `let` keyword to declare the incrementing variable `j`. The benchmark definition is:
```javascript
for(let x = 0; x < 1000; x++) {
    let j = 0;
    j++;
}
```
2. **"without let"`**: This benchmark does not use the `let` keyword and instead uses a simple assignment to increment variable `i`. The benchmark definition is:
```javascript
for(let x = 0; x < 1000; x++) {
    i++;
}
```
**Options Compared**

The two options being compared are:

* Using the `let` keyword to declare variables (`with let`)
* Not using the `let` keyword and instead relying on variable hoisting (without `let`)

**Pros and Cons**

Using the `let` keyword has some advantages:

* **Variable binding**: The `let` keyword ensures that the variable is bound to a specific scope, making it easier to understand and debug code.
* **Block scoping**: The `let` keyword introduces block scoping, which means that variables are only accessible within the scope of the loop.

However, using the `let` keyword also has some drawbacks:

* **Performance overhead**: In this simple benchmark, the performance difference between using `let` and not using it is likely to be small.
* **Additional complexity**: The `let` keyword requires additional syntax and can introduce more complex code structures.

Not using the `let` keyword and relying on variable hoisting has its own set of trade-offs:

* **Variable hoisting**: Variable hoisting can lead to unexpected behavior if not used carefully, especially when working with nested scopes.
* **Less explicit scope**: Without the `let` keyword, the scope of variables is not as explicitly defined, making it harder to understand and maintain code.

**Library**

There is no library explicitly mentioned in this benchmark. However, some libraries may use the `let` keyword or other features that could impact performance (e.g., Array.prototype.forEach()).

**Special JS Feature or Syntax**

The benchmark uses a simple loop with incrementing variables, which is a fundamental concept in JavaScript programming. There are no special features or syntax used beyond this.

**Other Alternatives**

If you're interested in exploring alternative approaches to this benchmark, here are some options:

* Use a different variable declaration keyword (e.g., `const`, `var`) and compare its performance.
* Add additional complexity to the loop (e.g., nested loops) and measure the impact on performance.
* Introduce external factors that affect performance (e.g., network latency, disk I/O).

Keep in mind that these alternatives may require significant modifications to the benchmark code and should be carefully evaluated for relevance and reliability.

Related benchmarks:

let or without let (2) (version: 0)

Comparing performance of: with let vs without let

Created: 6 months ago by: Guest

Jump to the latest result

with let

without let

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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