Benchmark: increment vs assignment

Script Preparation code:

let i = 0;

Tests:

increment
i++
assignment
i = 1

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
increment
assignment

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/135.0.0.0 Safari/537.36 Edg/135.0.0.0

Browser/OS: Chrome 135 on Windows

View result in a separate tab

Test name	Executions per second
increment	39504408.0 Ops/sec
assignment	40003292.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks!

**What is tested on the provided JSON?**

The provided JSON represents two individual test cases, which are used to compare the performance of increment (`i++`) versus assignment (`i = 1`). The script preparation code is the same for both test cases: `let i = 0;`. This means that both tests start with an initial value of `i` set to 0.

**Options compared**

The two options being compared are:

1. **Increment**: `i++`
2. **Assignment**: `i = 1`

These two approaches differ in how they modify the variable `i`.

**Pros and Cons of each approach:**

**Increment (i++)**

Pros:

* Can be optimized away by some compilers, resulting in a faster execution.
* Can lead to a more "JavaScript-like" behavior, as it avoids creating a temporary variable.

Cons:

* May not work correctly for all JavaScript engines or versions.
* Can result in a more complex code analysis due to the increment operation.

**Assignment (i = 1)**

Pros:

* Typically results in a simple and straightforward execution path.
* Often used in tutorials or examples to illustrate basic assignment operations.

Cons:

* Creates a temporary variable, which can lead to additional overhead.
* May not be optimized away by some compilers.

**Other considerations:**

* The `let` keyword is used in both scripts, which means the scope of `i` is block-level. This might affect the behavior or optimization of these tests.
* The script preparation code is set to `let i = 0;`, which initializes `i` to 0 before each test case. This ensures that both tests start with the same initial value.

**Library and purpose**

There doesn't seem to be any specific library used in this benchmark. However, some JavaScript engines or environments might have their own optimizations or quirks when it comes to increment operations. The `let` keyword is a standard feature introduced in ECMAScript 2015 (ES6), which allows block-level scoping.

**Special JS feature or syntax**

The `++` operator is an example of a **post-increment operator**, which increments the value after the expression has been evaluated. This is different from the traditional pre-increment operator (`i = i + 1;`). The use of `++` can lead to subtle performance differences due to how JavaScript engines optimize these operations.

**Benchmark preparation code and other alternatives**

The benchmark preparation code is already provided: `let i = 0;`.

Other alternatives for measuring performance might include:

* Using a timer function, like `Date.now()` or a dedicated library like `Benchmark.js`.
* Creating multiple iterations of the test case to increase the sample size.
* Testing different input values or edge cases to further stress the code.

I hope this explanation helps you understand the provided benchmark and its underlying concepts!

Related benchmarks:

increment vs assignment (version: 0)

Comparing performance of: increment vs assignment

Created: 2 years ago by: Guest

Jump to the latest result

increment

assignment

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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