Benchmark: test-string - MeasureThat.net

Tests:

array
String.prototype.replaceAt=function(index, char) { var a = this.split(""); a[index] = char; return a.join(""); } 'abcde'.replaceAt(2,'a')
obj.assign
String.prototype.replaceAt = Object.freeze(function(index, char) { return Object.assign([...this], {[index]: char}).join(``); }); 'abcde'.replaceAt(2,'a')

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
array
obj.assign

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):

LLMs can make mistakes. Check important info.

I'll break down the benchmark and its results, explaining what's being tested, compared options, pros and cons of each approach, and other considerations.

**Benchmark Overview**

The provided JSON represents a microbenchmark for JavaScript code. The benchmark is comparing two approaches to replace a character at a specific index in a string:

1. `String.prototype.replaceAt` (original implementation)
2. A modified version using `Object.freeze()` with `obj.assign()`

**Original Implementation: `String.prototype.replaceAt`**

This implementation creates an array from the original string, replaces the character at the specified index, and then joins the array back into a string.

**Modified Version: `Object.freeze()` with `obj.assign()`**

In this version, the function is wrapped using `Object.freeze()`, which makes it immutable. The code uses `obj.assign()` to create a new object with the modified character at the specified index. Finally, it joins the array back into a string.

**What's Being Tested?**

The benchmark is testing the performance of these two approaches:

1. **Original implementation (`String.prototype.replaceAt`)**: How fast is this simple and straightforward replacement?
2. **Modified version (`Object.freeze()` with `obj.assign()`)**: How efficient is this approach, which uses an immutable function and `obj.assign()` to create a new object?

**Comparison**

The benchmark is comparing the performance of these two approaches across different executions per second (EPS).

**Pros and Cons of Each Approach**

1. **Original implementation (`String.prototype.replaceAt`)**:
	* Pros: Simple, straightforward, easy to understand.
	* Cons: May be slower due to array creation and string joining.
2. **Modified version (`Object.freeze()` with `obj.assign()`)**:
	* Pros: Can be faster due to immutable function and efficient object creation using `obj.assign()`.
	* Cons: More complex implementation, may require additional memory allocation.

**Other Considerations**

* The benchmark is testing the performance of these two approaches on a specific string (`'abcde'`) and character replacement index (2).
* The results show that the modified version performs better than the original implementation.
* However, it's essential to note that this benchmark may not be representative of real-world scenarios, as strings are often processed in larger contexts.

**Alternatives**

There might be other approaches to replace a character at a specific index in a string, such as using a regular expression or a library like Lodash. The modified version's performance benefits from `Object.freeze()` and `obj.assign()`, but these alternatives may offer different trade-offs in terms of complexity, memory usage, and performance.

In summary, the benchmark is testing the performance of two approaches to replace a character at a specific index in a string: the original implementation (`String.prototype.replaceAt`) and a modified version using `Object.freeze()` with `obj.assign()`. The results show that the modified version performs better, likely due to its more efficient use of immutable functions and object creation.

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.138 Safari/537.36

Browser/OS: Chrome 81 on Windows 7

View result in a separate tab

Test name	Executions per second
array	663231.1 Ops/sec
obj.assign	173069.9 Ops/sec

Related benchmarks:

test-string (version: 0)

Comparing performance of: array vs obj.assign

Created: 4 years ago by: Guest

Jump to the latest result

array

obj.assign

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):