Benchmark: for of string vs for index

Script Preparation code:

var baseStr = 'abcde12302323weqweasdajncasdkjaskdkasdqweio'

Tests:

normal for
var arr = [] for(let i=0,len = baseStr.length;i<len;i++){ arr[i] = baseStr[i] }
normal for with chatAt
var arr = [] for(let i=0,len = baseStr.length;i<len;i++){ arr[i] = baseStr.charAt(i) }
for of
var arr = [] for(const char of baseStr){ arr[i] = char }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
normal for
normal for with chatAt
for of

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

The provided JSON represents a JavaScript microbenchmark, specifically comparing three different approaches to iterate over a string: traditional `for` loop with indexing (`arr[i] = baseStr[i]`), traditional `for` loop with `charAt()` method (`arr[i] = baseStr.charAt(i)`), and the new `for...of` loop syntax (using a string as an iterable).

**Options being compared:**

1. Traditional `for` loop with indexing (`normal for`):
	* Pros:
		+ Well-established and widely supported syntax.
		+ Can be used in older browsers that don't support `for...of`.
	* Cons:
		+ More verbose and less readable than the other options.
2. Traditional `for` loop with `charAt()` method (`normal for with chatAt`):
	* Pros:
		+ Still relatively concise, especially when compared to the indexing approach.
3. New `for...of` loop syntax (using a string as an iterable) (`for of`):
	* Pros:
		+ More concise and readable than traditional loops.
		+ Allows for more flexibility in iterating over arrays or strings.

**Library usage:**

There is no explicit library usage mentioned in the provided benchmark definitions. However, the `baseStr` variable is defined using template literals (string interpolation), which uses a modern JavaScript feature (ES6+). This suggests that the benchmark might be testing the performance of modern JavaScript features on older browsers or systems.

**Special JS feature or syntax:**

The `for...of` loop syntax is a relatively recent addition to JavaScript, introduced in ES2015. It allows for more concise iteration over arrays or strings using the `of` keyword. The template literals (string interpolation) used to define `baseStr` are also a modern feature, introduced in ES6.

**Benchmark preparation code:**

The script preparation code defines an empty array `arr` and then uses one of the three loop approaches to iterate over the `baseStr` string, assigning each character to the corresponding index in the `arr` array.

**Other alternatives:**

If you want to test alternative iteration methods or syntaxes, here are a few options:

* Using a library like Lodash or Underscore.js for iteration
* Testing other loop constructs, such as while loops or do-while loops
* Investigating different string manipulation techniques, such as using `substring()` or regular expressions

Note that the choice of alternatives will depend on the specific goals and requirements of your benchmarking effort.

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/118.0.0.0 Safari/537.36

Browser/OS: Chrome 118 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
normal for	604684.6 Ops/sec
normal for with chatAt	603571.4 Ops/sec
for of	3457137.8 Ops/sec

Related benchmarks:

for of string vs for index (version: 0)

Comparing performance of: normal for vs normal for with chatAt vs for of

Created: one year ago by: Guest

Jump to the latest result

normal for

normal for with chatAt

for of

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):