Benchmark: Substring compare

Script Preparation code:

const strings = []
, length = 1000
, {substring} = ""
, args = [0, 3]
for (let i = 0; i < length; i++)
  strings[i] = btoa(Math.random()).substring(3)
  
function nop(_) {}

let x

Tests:

.substring
for (let i = 0; i < length; i++) { const str = strings[i] x = str.substring(0, 3) }
.substr
for (let i = 0; i < length; i++) { const str = strings[i] x = str.substr(0, 3) }
substring.call
for (let i = 0; i < length; i++) { const str = strings[i] x = substring.call(str, 0, 3) }
substring.apply
for (let i = 0; i < length; i++) { const str = strings[i] x = substring.apply(str, args) }
.slice
for (let i = 0; i < length; i++) { const str = strings[i] x = str.slice(0, 3) }
literal
for (let i = 0; i < length; i++) { const str = strings[i] x = `${str[0]}${str[1]}${str[2]}` }
addition
for (let i = 0; i < length; i++) { const str = strings[i] x = str[0] + str[1] + str[2] }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
.substring
.substr
substring.call
substring.apply
.slice
literal
addition

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

I'll break down the explanation into manageable parts.

**Benchmark Definition**

The provided JSON defines a benchmarking test suite for comparing the performance of different methods to extract substrings from a string in JavaScript. The test is called "Substring compare" and it's described as:

".substring", ".substr", `slice`, `substring.call`, string literal, addition"

This means that the test compares the execution speed of six different approaches:

1. `.substring`
2. `.substr`
3. `slice`
4. `substring.call`
5. Using a string literal (concatenating strings)
6. Adding characters to create a new string

**Options Compared**

Here's a brief overview of each option and their pros and cons:

1. `.substring`:
	* Pros: widely supported, efficient for modern browsers.
	* Cons: may not be as fast as other methods in older browsers.
2. `.substr`:
	* Pros: simple, widely supported.
	* Cons: may have performance issues due to string creation overhead.
3. `slice`:
	* Pros: efficient, supports negative indices.
	* Cons: less widely supported than `.substring` or `.substr`.
4. `substring.call` and `substring.apply`:
	* These methods are essentially the same as `.substring`, but with a twist: they take an additional argument (a callback function) to control the extraction process. The performance difference is negligible.
5. String Literal (`+`):
	* Pros: simple, works in all browsers.
	* Cons: creates a new string object, which can be slower than other methods.

**Library and Special Features**

There are no libraries mentioned in the provided JSON, but it's worth noting that some libraries like Lodash or underscore.js provide similar functionality to these methods.

The test also uses special JavaScript features:

1. `btoa` (base64 encoding): used to generate random strings.
2. `Math.random()`: used to generate random numbers.

**Other Considerations**

When creating benchmarks, it's essential to consider factors like:

* Test setup and teardown
* Number of iterations and runs
* Browser and platform support
* Performance metrics (e.g., execution time, throughput)

In this case, the benchmarker has generated a large number of random strings, which helps to ensure a representative sample. However, it's still crucial to validate the results across multiple browsers and platforms.

**Alternatives**

Some alternative approaches for substring extraction include:

1. Using regular expressions (`RegExp`)
2. Implementing custom substring extraction functions
3. Leveraging web workers or parallel processing for performance-critical code

Keep in mind that these alternatives might have trade-offs in terms of complexity, maintainability, or browser support.

I hope this explanation helps you understand the benchmarking test suite!

Related benchmarks:

Substring compare (version: 0)

`.substring`, `.substr`, `slice`, `substring.call`, string literal, addition

Comparing performance of: .substring vs .substr vs substring.call vs substring.apply vs .slice vs literal vs addition

Created: 4 years ago by: Registered User

Jump to the latest result

.substring

.substr

substring.call

substring.apply

.slice

literal

addition

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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