Benchmark: reassign vs create new

Tests:

new variable
var x = 10; var x2 = x*x; var y = 10; var y2 = y*y; var z = 10; var z2 = z*z; var h = 10; var h2 = h*h;
reassign
var x = 10; var x2 = x*x; x = 11; x2 = x*x; x = 12; x2 = x*x; x = 13; x2 = x*x;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
new variable
reassign

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's dive into the world of MeasureThat.net and explore the provided benchmark.

**Benchmark Overview**

The benchmark is designed to compare two approaches: creating a new variable (`new variable`) and reassigning an existing variable (`reassign`).

**Script Preparation Code**

Since there is no script preparation code provided, we'll assume that it's empty. This means that the JavaScript engine will execute from the start of the benchmark script.

**Individual Test Cases**

There are two test cases:

1. `new variable`: This test case creates a new variable `x2` and assigns its value as the square of `x`. The same process is repeated for variables `y`, `z`, and `h`.
2. `reassign`: This test case reassigns the value of an existing variable (`x`) multiple times, recalculating the square of `x` each time.

**Library Usage**

The benchmark uses a library to perform calculations: none explicitly mentioned, but the use of arithmetic operators (`*`, `=`) implies that the JavaScript engine is using its built-in math functions. No external libraries are required for these simple operations.

**Special JS Features/Syntax**

There's no special JavaScript feature or syntax used in this benchmark. The code follows standard JavaScript syntax and doesn't utilize any advanced features like async/await, arrow functions, or classes.

**Approaches Compared**

The two test cases compare the performance of creating a new variable versus reassigning an existing variable:

* `new variable`: Creates a new variable each time, recalculating its value from scratch.
* `reassign`: Reuses the same variable and recalculates its value by reassigning it.

**Pros and Cons**

**`new variable` approach:**

Pros:

* Simplifies code; no need to worry about modifying existing variables
* Reduces potential issues with variable scope or hoisting

Cons:

* Creates a new object each time, which can lead to increased memory usage and garbage collection overhead
* Re-calculates the value from scratch, which may be slower than reusing an existing value

**`reassign` approach:**

Pros:

* Reuses the same object, reducing memory allocation and garbage collection overhead
* Can potentially be faster since only a single reassignment is needed

Cons:

* Requires careful management of variable scope and hoisting to avoid issues with modifications being lost or overwritten
* Can lead to more complex code, making it harder to understand and maintain

**Considerations**

When deciding between these approaches, consider the trade-offs between memory usage, performance, and code complexity. In general, creating a new variable might be preferred for simple cases where readability is more important than efficiency, while reassigning an existing variable might be better suited for situations where performance is critical.

**Alternatives**

Other alternatives to measure this benchmark could include:

* Using a different programming language or JavaScript variant with different performance characteristics
* Experimenting with different data types (e.g., numbers vs. objects) to see how they affect performance
* Comparing the performance of the `new variable` and `reassign` approaches in more complex scenarios, such as loops or nested calculations

Latest run results:

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

User agent: Mozilla/5.0 (Android 12; Mobile; rv:103.0) Gecko/103.0 Firefox/103.0

Browser/OS: Firefox Mobile 103 on Android

View result in a separate tab

Test name	Executions per second
new variable	1068036736.0 Ops/sec
reassign	1037105984.0 Ops/sec

Related benchmarks:

reassign vs create new (version: 0)

Comparing performance of: new variable vs reassign

Created: 6 years ago by: Guest

Jump to the latest result

new variable

reassign

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):