Benchmark: substring vs substring+

Script Preparation code:

var IDS = ["report_1", "report_1", "report_1", "report_1","report_1","report_1","report_1","report_1","report_1", "report_dsdsdssds_1", "report_dsdsdsds_1", "report_1", "report_1","report_1","report_1","report_1","report_1","report_1", "report_random_bla_foo_12321312", "report_random_bla_foo_12321312","report_random_bla_foo_12321312","report_random_bla_foo_12321312","report_random_bla_foo_12321312","report_random_bla_foo_12321312","report_random_bla_foo_12321312","report_random_bla_foo_12321312"];

Tests:

substring + extra obj
function splitCollectionMemberKey(key) { const underscoreIndex = key.indexOf('_'); if (underscoreIndex === -1) { throw new Error(`Invalid ${key} key provided, only collection keys are allowed.`); } return [key.substring(0, underscoreIndex + 1), key.substring(underscoreIndex + 1)]; } IDS.forEach((id) => splitCollectionMemberKey(id));
substring simple
function getCollectionKey(key) { if (!key) { return ''; } const lastUnderscoreIndex = key.lastIndexOf('_'); if (lastUnderscoreIndex === -1) { return key; } return key.substring(0, lastUnderscoreIndex); } IDS.forEach((id) => getCollectionKey(id));

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
substring + extra obj
substring simple

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 break down the provided JSON data and explain what is being tested, compared, and discussed.

**Benchmark Definition**

The benchmark definition represents two different approaches to extracting part of a string using JavaScript's `substring()` method.

1. **`splitCollectionMemberKey(key)`**: This function splits the input `key` into two parts: before and after the first underscore (`_`). It uses `indexOf()`, which searches for the first occurrence of `_` in the string, and then returns a new array with these two parts.
2. **`getCollectionKey(key)`**: This function also extracts part of a string using `substring()` but uses `lastIndexOf()` to find the last index of `_` (if it exists) and then returns only up to that index.

**Comparison**

The two functions are being compared in terms of performance, specifically how many times they can execute per second. The benchmark is run on a set of test cases (`IDS`) using each function.

**Options Compared**

Two options are being compared:

1. Using `indexOf()` and returning two parts (as in `splitCollectionMemberKey(key)`).
2. Using `lastIndexOf()` and returning only up to the last index of `_` (as in `getCollectionKey(key)`).

**Pros and Cons**

* **Using `indexOf()`**: Pros - simple, easy to understand; Cons - may be slower than other methods due to string search overhead.
* **Using `lastIndexOf()`**: Pros - potentially faster since it only searches up to the last occurrence of `_`; Cons - may require more code complexity if not used carefully.

**Other Considerations**

In terms of best practice, using `indexOf()` might be considered less efficient than other methods like `startsWith()` or regular expressions, but for this specific use case, the performance difference between these two approaches is relatively small. Additionally, considering code readability and maintainability, `getCollectionKey(key)` is a more straightforward implementation.

**Library Usage**

There doesn't seem to be any external library used in the benchmarked code snippets, so no special libraries are being tested or compared here.

**Special JS Features/Syntax**

No specific JavaScript features or syntaxes are being highlighted or tested. The focus is on comparing simple string manipulation approaches between `substring()` and two different indexing methods (`indexOf()`, `lastIndexOf()`).

**Alternatives**

Other alternatives for extracting part of a string could include:

1. Using regular expressions (e.g., `/_+/`.exec(key)[0])
2. Utilizing the `startsWith()` method
3. Employing other string manipulation techniques, like concatenation and indexing

However, these alternatives are not being tested in this specific benchmark.

Overall, this benchmark aims to compare two simple yet distinct approaches for extracting part of a string using JavaScript's `substring()` method.

Latest run results:

Run details: (Test run date: 5 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
substring + extra obj	4483415.0 Ops/sec
substring simple	2136983.2 Ops/sec

Related benchmarks:

substring vs substring+ (version: 0)

Comparing performance of: substring + extra obj vs substring simple

Created: 5 months ago by: Guest

Jump to the latest result

substring + extra obj

substring simple

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):