Benchmark: Remove last item from / separated string

Script Preparation code:

var str = 'lorem/ipsum/dolor/sit/amet/consectetur/adipiscing/elit/sed/do/eiusmod/tempor/incididunt/ut/labore/et/dolore/magna/aliqua/ut/enim/ad/minim/veniam/quis/nostrud/exercitation/ullamco/laboris/nisi/ut/aliquip/ex/ea/commodo/consequat/duis/aute/irure/dolor/in/reprehenderit/in/voluptate/velit/esse/cillum/dolore/eu/fugiat/nulla/pariatur/excepteur/sint/occaecat/cupidatat/non/proident/sunt/in/culpa/qui/officia/deserunt/mollit/anim/id/est/laborum/base/resource/collection/video-collection'

Tests:

With Regexp
str.replace(/\/[^/]*$/, '')
With Regexp of smaller scope
str.replace(/\/[a-z-]*$/, '')
With for-loop
var index = -1; for (var i = str.length - 1; i >= 0; i--) { if (str[i] === '/') { i = index; break; } } str.substring(0, index);
With for-loop (initialized length)
var index = -1; lastIndex = str.length - 1; for (var i = lastIndex; i > -1; i--) { if (str[i] === '/') { i = index; break; } } str.substring(0, index);
With lastIndexOf and substring
str.substring(0, str.lastIndexOf('/'))
With lastIndexOf and slice
str.slice(0, str.lastIndexOf('/'))
With split, slice, join
str.split('/').slice(0, -1).join('/')
With split, pop, join
var a = str.split('/') a.pop() a.join('/')

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
With Regexp
With Regexp of smaller scope
With for-loop
With for-loop (initialized length)
With lastIndexOf and substring
With lastIndexOf and slice
With split, slice, join
With split, pop, join

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 benchmark and analyze each test case.

**Benchmark Definition**

The benchmark is designed to measure the performance of different approaches for removing the last item from a string that contains '/' separated items.

**Options Compared**

The following options are compared:

1. **With Regexp**: Using regular expressions to find and remove the last '/'.
2. **With Regexp of smaller scope**: Using a modified version of the previous approach with a smaller scope (e.g., only matching one character instead of two).
3. **With for-loop**: Using a traditional loop-based approach to iterate through the string and find the last '/'.
4. **With for-loop (initialized length)**: Initializing the loop counter with the last index of the string before starting the iteration.
5. **With lastIndexOf and substring**: Using the `lastIndexOf` method to find the position of the last '/' and then using `substring` to extract the remaining part of the string.
6. **With lastIndexOf and slice**: Similar to the previous approach, but using `slice` instead of `substring`.
7. **With split, slice, join**: Using the `split` method to divide the string into an array, popping off the last item, and then joining the remaining items back together.

**Pros and Cons**

Here's a brief summary of the pros and cons for each approach:

* **With Regexp**: Fast and efficient, but may be slower for very large strings due to the overhead of regular expression parsing.
* **With Regexp of smaller scope**: Similar performance to the previous approach, but with a slightly reduced scope which might make it more predictable and easier to understand.
* **With for-loop**: Traditional loop-based approach that is easy to understand but may be slower than the other approaches due to the overhead of indexing and decrementing.
* **With for-loop (initialized length)**: Similar performance to the previous approach, but with a slight optimization by initializing the loop counter with the last index.
* **With lastIndexOf and substring**: Fast and efficient, but requires extra method calls which might incur some overhead.
* **With lastIndexOf and slice**: Similar performance to the previous approach, but using `slice` instead of `substring`.
* **With split, slice, join**: May be slower than other approaches due to the overhead of creating an array and joining its elements.

**Observations**

From the benchmark results, we can observe that:

* The approaches with regular expressions (Regexp) are generally fast and efficient.
* The approach with `lastIndexOf` and substring is also very fast and efficient.
* The traditional loop-based approach (`With for-loop`) is slower than the other approaches but still quite reasonable.
* Initializing the loop counter with the last index in the `for-loop` approach provides a slight performance improvement.

Overall, the benchmark highlights the importance of choosing the right algorithmic approach based on the specific requirements and constraints of the problem.

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.149 Safari/537.36

Browser/OS: Chrome 80 on Windows

View result in a separate tab

Test name	Executions per second
With Regexp	495440.1 Ops/sec
With Regexp of smaller scope	504375.4 Ops/sec
With for-loop	419858.5 Ops/sec
With for-loop (initialized length)	342976.7 Ops/sec
With lastIndexOf and substring	3019218.0 Ops/sec
With lastIndexOf and slice	3054037.2 Ops/sec
With split, slice, join	254613.0 Ops/sec
With split, pop, join	260353.4 Ops/sec

Related benchmarks:

Remove last item from / separated string (version: 0)

Comparing performance of: With Regexp vs With Regexp of smaller scope vs With for-loop vs With for-loop (initialized length) vs With lastIndexOf and substring vs With lastIndexOf and slice vs With split, slice, join vs With split, pop, join

Created: 4 years ago by: Registered User

Jump to the latest result

With Regexp

With Regexp of smaller scope

With for-loop

With for-loop (initialized length)

With lastIndexOf and substring

With lastIndexOf and slice

With split, slice, join

With split, pop, join

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):