Benchmark: charCodeAt vs [] comparison

Script Preparation code:

var str = "some string heresome string heresome string heresome string heresome string heresome string heresome string heresome string heresome string heresome string heresome string heresome string heresome string heresome string heresome string heresome string heresome string heresome string heresome string here"

Tests:

charCodeAt(0)
str.charCodeAt(0) === 115
[0]
str[0] === 's'

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
charCodeAt(0)
[0]

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Safari/537.36

Browser/OS: Chrome 134 on Windows

View result in a separate tab

Test name	Executions per second
charCodeAt(0)	156058208.0 Ops/sec
[0]	156074368.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested, compared, and considered.

**Benchmark Definition**

The benchmark defines two test cases:

1. `charCodeAt(0) === 115`
2. `[0] === 's'`

These test cases are comparing the performance of two different approaches to access the first character of a string in JavaScript:

* `charCodeAt(0)` : This method returns the Unicode code point for the character at the specified index (in this case, index 0). It's often used when you know the exact index of the character you're interested in.
* `[0]` : This syntax is called array indexing or bracket notation. It accesses the first element (or property) of an object or array.

**Options being compared**

The benchmark is comparing the performance of these two approaches:

* `charCodeAt(0)` vs `[0]`
* The first test case measures the time it takes to access the first character using `charCodeAt(0)`.
* The second test case measures the time it takes to access the first character using `[0]`.

**Pros and Cons**

Here are some pros and cons of each approach:

* `charCodeAt(0)`:
	+ Pros: Fast, lightweight, and easy to use when you know the exact index.
	+ Cons: May not be available on all platforms (e.g., IE 8), and can lead to slower performance if used extensively in loops.
* `[0]`:
	+ Pros: More readable and expressive than `charCodeAt(0)`, and is widely supported across browsers.
	+ Cons: May be slightly slower due to the overhead of parsing the expression.

**Library/Language Features**

There are no libraries or language features being tested in this benchmark. The focus is on comparing the performance of two basic JavaScript syntaxes.

**Special JS Feature/Syntax**

There are no special JS features or syntax being used in this benchmark.

**Other Alternatives**

If you're interested in exploring alternative approaches, here are a few options:

* `str.charAt(0)`: This method returns the character at the specified index. It's similar to `charCodeAt(0)` but provides more readable code.
* `String.prototype.at()`: This is a newer method introduced in JavaScript ES6 that allows accessing characters using a more concise syntax, e.g., `str.at(0)`. However, it's not widely supported across browsers yet.

In summary, the benchmark is comparing the performance of two basic JavaScript syntaxes for accessing the first character of a string. While there are some pros and cons to each approach, `[0]` provides more readable code while `charCodeAt(0)` can be faster in certain cases.

Related benchmarks:

charCodeAt vs [] comparison (version: 0)

Comparing performance of: charCodeAt(0) vs [0]

Created: 2 years ago by: Guest

Jump to the latest result

charCodeAt(0)

[0]

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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