Benchmark: charCodeAt vs codePointAt

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
str.charCodeAt(20)
codePointAt
str.codePointAt(20)

Historical Performance Data aggregated from 15 community runs

Desktop Results:

Chrome 15 runs

codePointAt

28.6M/s

charCodeAt

28.3M/s

View exact numbers

✓ codePointAt: 28,550,186 ops/sec
• charCodeAt: 28,309,708 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
charCodeAt
codePointAt

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 9 months ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/141.0.0.0 Safari/537.36

Browser/OS: Chrome 141 on Linux

View result in a separate tab

codePointAt

196.9M/s

charCodeAt

186.2M/s

View exact numbers

Test name	Executions per second
✓ codePointAt	196,942,528 Ops/sec
charCodeAt	186,161,328 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 is being tested.

**Benchmark Overview**

The benchmark is comparing two JavaScript methods: `charCodeAt` and `codePointAt`. Both methods are used to access individual code points in a string, but they have different approaches and use cases.

**Options Compared**

Two options are compared:

1. **`charCodeAt`**: This method returns the Unicode code point of an individual character at a specified index in the string.
2. **`codePointAt`**: This method returns the Unicode code point of an individual code point at a specified index (from 0 to 10FFFF) in the string.

**Pros and Cons**

Here are some pros and cons for each approach:

* `charCodeAt`:
	+ Pros: Simple, widely supported, and fast.
	+ Cons: Only works with Unicode characters up to U+FFFF, which may not cover all possible code points (e.g., emojis).
* `codePointAt`:
	+ Pros: Can handle a wider range of Unicode code points, including emojis.
	+ Cons: May be slower due to the need to check the input index against the maximum allowed value (10FFFF).

**Library and Special JS Features**

Neither `charCodeAt` nor `codePointAt` uses any external libraries. However, both methods rely on JavaScript's built-in Unicode support.

* The benchmark does not use any special JavaScript features beyond standard syntax.
* Note that the benchmark tests for support in Chrome 130, which may have some subtle or experimental optimizations not reflected here

**Other Alternatives**

For similar comparisons, other benchmarks might test:

1. `indexOf` vs `charCodeAt`
2. `substr` vs string slicing (`slice()`)
3. `match()` vs regular expressions
4. Different methods for iterating over arrays (e.g., `forEach()`, `for...in`, `while`)

**Benchmark Preparation Code**

The provided JavaScript code creates a long string using the "str" variable, which is then used as input for both benchmarks.

```javascript
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 here";
```

This code is likely intended to warm up the JavaScript engine and ensure that both benchmarks are executed under similar conditions.

Let me know if you'd like further clarification!

charCodeAt vs codePointAt (version: 0)

Comparing performance of: `charCodeAt vs codePointAt`

Created: 5 years ago by: Guest

Go to the latest result

charCodeAt

codePointAt

Historical Performance Data aggregated from 15 community runs

Desktop Results:

Chrome 15 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

charCodeAt vs codePointAt (version: 0)

Comparing performance of: charCodeAt vs codePointAt

Created: 5 years ago by: Guest

Go to the latest result

charCodeAt

codePointAt

Historical Performance Data aggregated from 15 community runs

Desktop Results:

Chrome 15 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: `charCodeAt vs codePointAt`