Benchmark: charAt vs charCodeAt

Script Preparation code:

str = "F2"

Tests:

charAt
str.charAt(0) === 'F'
charCodeAt
str.charCodeAt(0) === 70

Historical Performance Data aggregated from 21 community runs

Desktop Results:

Chrome 12 runs

charCodeAt

48.3M/s

charAt

43.3M/s

Fastest: charCodeAt (1.1x faster)

View exact numbers

✓ charCodeAt: 48,310,540 ops/sec
• charAt: 43,275,224 ops/sec

Firefox 9 runs

charCodeAt

1227.3M/s

charAt

1209.8M/s

View exact numbers

✓ charCodeAt: 1,227,325,184 ops/sec
• charAt: 1,209,759,232 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
charAt
charCodeAt

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/136.0.0.0 Safari/537.36 EdgA/136.0.0.0

Browser/OS: Chrome 136 on Android

View result in a separate tab

charAt

83.3M/s

charCodeAt

82.8M/s

View exact numbers

Test name	Executions per second
✓ charAt	83,326,720 Ops/sec
charCodeAt	82,751,592 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 the pros/cons of each approach.

**Benchmark Definition**

The benchmark measures the performance difference between two JavaScript methods: `charAt` and `charCodeAt` when used to access individual characters in a string.

**Script Preparation Code**
```javascript
str = "F2";
```
A simple string variable is created with the value `"F2"`.

**Html Preparation Code**

There is no HTML preparation code provided, so we'll assume that this benchmark is running in a headless environment or doesn't require any specific HTML setup.

**Test Cases**

The benchmark consists of two test cases:

1. `charAt`
```javascript
str.charAt(0) === 'F'
```
This test case uses the `charAt` method to access the first character of the string and then compares it to `'F'`.

2. `charCodeAt`
```javascript
str.charCodeAt(0) === 70
```
This test case uses the `charCodeAt` method to get the Unicode code point of the first character of the string (which is `F`) and then compares it to `70`.

**Library Used**

There is no explicit library mentioned in the benchmark definition. However, it's likely that the benchmark is using a JavaScript engine or runtime environment that provides these methods.

**Special JS Feature/Syntax**

The use of `===` for equality comparison is not specific to any particular feature or syntax in JavaScript.

**Other Alternatives**

If we wanted to write this benchmark ourselves, here are some alternatives:

1. Using `substr` instead of `charAt`: This would involve comparing the result of `str.substr(0, 1)` to `'F'`.
2. Using a regular expression: This would involve creating a regex pattern that matches the first character of the string and then comparing it to `'F'`.

**Pros/Cons**

Here are some pros and cons for each approach:

* **charAt**: Pros:
	+ More readable code
	+ Easier to understand the intent of the test case
*   Cons:
	+ May have overhead due to method call and argument passing
*   **charCodeAt**: Pros:
	+ Less overhead due to no method call or argument passing
*   Cons:
	+ May be less readable due to using a non-standard property access
*   Using `substr` instead of `charAt`: Pros:
	+ Similar performance characteristics to `charAt`
*   Cons:
	+ More verbose code
*   Using a regular expression: Pros:
	+ Flexibility in matching patterns
*   Cons:
	+ May have additional overhead due to regex processing

Overall, the choice between these approaches depends on the specific requirements of the benchmark and the trade-offs between performance, readability, and maintainability.

charAt vs charCodeAt (version: 0)

Comparing performance of: `charAt vs charCodeAt`

Created: 5 years ago by: Guest

Go to the latest result

charAt

charCodeAt

Historical Performance Data aggregated from 21 community runs

Desktop Results:

Chrome 12 runs

Firefox 9 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

charAt vs charCodeAt (version: 0)

Comparing performance of: charAt vs charCodeAt

Created: 5 years ago by: Guest

Go to the latest result

charAt

charCodeAt

Historical Performance Data aggregated from 21 community runs

Desktop Results:

Chrome 12 runs

Firefox 9 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Related benchmarks

Comparing performance of: `charAt vs charCodeAt`