Benchmark: Get first and last char on a string

Script Preparation code:

var str = "abcdefghijklmnopqrstuvwxyz"

Tests:

index of
var i = str.indexOf(0) var ii = str.indexOf(str.length -1)
simple indexing
var i = str[0] var ii = str[str.length -1]
substring
var i = str.substring(0, 1) var ii = str.substring(str.length - 2, str.length - 1)
substr
var i = str.substr(0, 1) var ii = str.substr(str.length - 2, 1)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
index of
simple indexing
substring
substr

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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

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Let's break down the benchmark and explain what is being tested, compared, and its pros/cons.

**Benchmark Definition**

The benchmark definition json provides information about the test case:

* `Name`: The name of the benchmark, which is "Get first and last char on a string".
* `Description`: An empty description, but this can be useful for human interpretation.
* `Script Preparation Code` and `Html Preparation Code`: These are used to prepare the script before running the test. In this case, the script preparation code sets up a string variable `str` with a fixed value `"abcdefghijklmnopqrstuvwxyz"`.

**Individual Test Cases**

The benchmark definition also includes an array of individual test cases:

* Each test case has a `Benchmark Definition`, which is a JavaScript snippet that simulates the operation being measured.
* The test cases are:
	+ "index of": Tests finding the index of the first and last characters (0 and -1) in the string using `str.indexOf(0)` and `str.indexOf(str.length - 1)`.
	+ "simple indexing": Tests accessing the first and last characters directly by index (using square brackets `[]`) at indices 0 and `str.length - 1`.
	+ "substring": Tests creating substrings using `str.substring(0, 1)` and `str.substring(str.length - 2, str.length - 1)`.
	+ "substr": Tests creating substrings using `str.substr(0, 1)` and `str.substr(str.length - 2, 1)`.

**Comparison of Approaches**

The test cases compare the performance of different approaches to achieve similar results:

* **Finding index**: Using `str.indexOf()` vs. direct indexing (`[]`).
	+ Pros/Cons:
		- `indexOf()`: More robust and flexible, can handle negative indices and returns -1 for non-existent characters.
		- Direct indexing: Faster, but more brittle and may not work for all inputs (e.g., empty strings or non-string values).
* **Substring creation**: Using `substring()` vs. `substr()`.
	+ Pros/Cons:
		- `substring()`: More modern and widely supported in JavaScript engines.
		- `substr()`: Legacy method still supported, but may be slower and less efficient.

**Library Usage**

There is no explicit library usage mentioned in the benchmark definition or test cases. However, it's worth noting that the use of `indexOf()` implies the use of the DOM methods, which are typically provided by the browser.

**Special JS Features/Syntax**

No special JavaScript features or syntax (e.g., ES6 classes, arrow functions) are used in the test cases. The code is written in a straightforward style suitable for older JavaScript versions and browsers.

**Other Alternatives**

To measure similar performance characteristics, you could consider using other approaches:

* Measure string slicing instead of substring creation.
* Test accessing elements at specific indices using `str.charAt()`.
* Compare results from different programming languages or frameworks (e.g., Python, C++, Java) to provide a broader comparison.

Keep in mind that these alternative approaches might not accurately represent the original test case's intent and may require modifications to achieve similar results.

Related benchmarks:

Get first and last char on a string (version: 0)

Comparing performance of: index of vs simple indexing vs substring vs substr

Created: 4 years ago by: Registered User

Jump to the latest result

index of

simple indexing

substring

substr

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):