Benchmark: startsWith + split VS slice + indexOf

Script Preparation code:

tests = ['v420', '420', 'v420.06.28', 'elonmusk']

Tests:

startsWith + split
tests.forEach((label) => { const labelWithoutV = label.startsWith('v') ? label.split('v')[1] : label console.log(labelWithoutV) })
slice + indexOf
tests.forEach((label) => { const labelWithoutV = label.slice(label.indexOf('v') + 1) console.log(labelWithoutV) })

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
startsWith + split
slice + indexOf

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/116.0

Browser/OS: Firefox 116 on Linux

View result in a separate tab

Test name	Executions per second
startsWith + split	30850.6 Ops/sec
slice + indexOf	32851.7 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks!

**Benchmark Definition**

The provided JSON defines two test cases: `startsWith + split` and `slice + indexOf`. The benchmark aims to compare the performance of two approaches for removing the prefix "v" from strings.

**Options Compared**

Two options are compared:

1. **startsWith + split**: This approach uses the `startsWith()` method to check if the string starts with "v", and then splits the string using `split('v')` to remove the prefix.
2. **slice + indexOf**: This approach uses the `indexOf()` method to find the index of "v" in the string, and then slices the string from that index using `slice(index)` to remove the prefix.

**Pros and Cons**

**.startsWith + split**

Pros:

* Readable and easy to understand code
* Does not rely on indexing or slicing, which can be slow for large strings

Cons:

* May lead to unnecessary splits if "v" is not present in the string
* Can be slower than `slice + indexOf` due to the overhead of splitting

**slice + indexOf**

Pros:

* Efficiently removes the prefix without creating a new string
* Avoids unnecessary work by only slicing from the index of "v"

Cons:

* Requires indexing and slicing, which can be slow for large strings
* Less readable than `startsWith + split`

**Library Usage**

There is no explicit library usage in this benchmark. However, it's worth noting that the `indexOf()` method is a built-in JavaScript method.

**Special JS Features/Syntax**

None mentioned in this specific benchmark. However, if you're interested in exploring other features or syntax, here are some examples:

* `let` and `const` declarations (as opposed to traditional `var`)
* Arrow functions (`=>`)
* Template literals (`${}`)

**Other Alternatives**

Some alternative approaches could be:

1. **Using a regular expression**: `s.replace(/^v/, '')`
2. **Using `match()` method**: `s.match(/^v/)[0]` (then slice the remaining string)
3. **Using `substring()` method**: `s.substring(s.indexOf('v') + 1)`

Keep in mind that these alternatives might have their own pros and cons, which would depend on the specific use case.

In conclusion, the benchmark provides a clear comparison between two approaches for removing prefixes from strings. The choice of approach ultimately depends on readability, performance, and personal preference.

Related benchmarks:

startsWith + split VS slice + indexOf (version: 0)

Comparing performance of: startsWith + split vs slice + indexOf

Created: 3 years ago by: Registered User

Jump to the latest result

startsWith + split

slice + indexOf

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):