Benchmark: 'of' vs indexed charAt() to iterate characters in a string

Script Preparation code:

var testString = 'abcdefghijklmnopqrstuvwxyz';

Tests:

char of
for (char of testString) console.log(char);
indexed charAt
for (i = 0; i < testString.length; i++) console.log(testString.charAt(i));

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
char of
indexed charAt

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/111.0

Browser/OS: Firefox 111 on Ubuntu

View result in a separate tab

Test name	Executions per second
char of	3735.7 Ops/sec
indexed charAt	3911.2 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and its test cases.

**Benchmark Definition**

The benchmark is designed to compare two approaches for iterating through characters in a string:

1. Using a `for...of` loop (`char of`)
2. Using the `charAt()` method with an index variable (`indexed charAt`)

**Options Compared**

The two options being compared are:

* Using a `for...of` loop to iterate over the characters in the string. This approach is often used for iterating over iterable objects like arrays or strings.
* Using the `charAt()` method with an index variable to access individual characters in the string.

**Pros and Cons of Each Approach**

### char of

* **Pros:**
	+ More concise and expressive code
	+ Easier to read and understand, as it clearly conveys the intention of iterating over each character
* **Cons:**
	+ May be slower due to the overhead of creating an iterator object
	+ Not all browsers support `for...of` loops (although most modern ones do)

### indexed charAt

* **Pros:**
	+ Generally faster, as it uses a direct call to `charAt()` with an index
	+ Works in older browsers that don't support `for...of`
* **Cons:**
	+ Code is less concise and more verbose
	+ May be less readable, especially for those not familiar with the `charAt()` method

**Library/Functionality Used**

None of the test cases use any external libraries or functions.

**Special JS Feature/Syntax**

The test case uses the `for...of` loop syntax, which is a relatively recent feature introduced in ECMAScript 2015 (ES6). This syntax allows for iterating over iterable objects like arrays or strings without needing an index variable.

**Other Alternatives**

If you wanted to benchmark other approaches for iterating through characters in a string, some alternatives could be:

* Using `Array.prototype.forEach()`
* Using a traditional `for` loop with an index variable
* Using a library like `lodash` or `underscore`, which provide utility functions for working with arrays and strings.

However, it's worth noting that the `for...of` loop is generally the most efficient and idiomatic way to iterate over characters in a string, making it a good choice for benchmarking purposes.

Related benchmarks:

'of' vs indexed charAt() to iterate characters in a string (version: 0)

Comparing performance of: char of vs indexed charAt

Created: 2 years ago by: Guest

Jump to the latest result

char of

indexed charAt

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):