Benchmark: String from Charcode test

Script Preparation code:

var chars = [239,15,2,1,227,15,118,2,68,63,49,59,56,90,0,44,15,143,1,206,15,251,7,255,56,15,43,2,206,15,225,0,255,74,15,135,3,255,56,15,74,1,71,15,0,3,255,74,15,92,1,242,15,172,8,44,15,63,0,107,15,194,1,242,15,5,1,224,15,118,2,65,15,184,11,255,17,63,49,59,56,234,6,71,15,90,0,218,15,180,3,224,15,243,0,255,56,15,42,3,218,15,237,0,161,15,235,2,255,56,15,74,1,255,8,15,3,9,65,15,84,0,86,15,215];

Tests:

For-loop
var s = ""; for(var i=0,l=chars.length; i<l; i++) s += String.fromCharCode(chars[i]);
String.fromCharCode.apply
var s = String.fromCharCode.apply(null, chars);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
For-loop
String.fromCharCode.apply

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 10 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.5 Safari/605.1.15

Browser/OS: Safari 18 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
For-loop	1583062.9 Ops/sec
String.fromCharCode.apply	3581295.8 Ops/sec

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

LLMs can make mistakes. Check important info.

**Overview of the Benchmark**

The provided benchmark, "String from Charcode test", measures the performance of two approaches to convert an array of character codes into a string in JavaScript. The benchmark is designed to compare the performance of using a `for` loop versus the `String.fromCharCode.apply()` method.

**Script Preparation Code**

The script preparation code consists of a single line that defines an array of character codes, `chars`. This array will be used as input for both test cases.

```javascript
var chars = [239,15,2,1,227,15,118,2,68,63,49,59,56,90,0,44,15,143,1,206,15,251,7,255,56,15,43,2,206,15,225,0,255,74,15,135,3,255,56,15,74,1,71,15,0,3,255,74,15,92,1,242,15,172,8,44,15,63,0,107,15,194,1,242,15,5,1,224,15,118,2,65,15,184,11,255,17,63,49,59,56,234,6,71,15,90,0,218,15,180,3,224,15,243,0,255,56,15,42,3,218,15,237,0,161,15,235,2,255,56,15,74,1,255,8,15,3,9,65,15,84,0,86,15,215];
```

This array contains a total of 36 character codes that will be used to construct the input string.

**Html Preparation Code**

There is no HTML preparation code provided for this benchmark. This means that the benchmark will not include any additional overhead such as parsing HTML or creating an HTML document.

**Test Cases**

The benchmark consists of two test cases:

1. **For-loop**: This test case uses a `for` loop to iterate over the character codes and construct the input string.
2. **String.fromCharCode.apply**: This test case uses the `String.fromCharCode.apply()` method to convert the array of character codes into a single string.

**Library and Purpose**

There is no external library used in this benchmark. However, the `String.fromCharCode` function is a built-in JavaScript function that converts a Unicode code point to a corresponding UTF-16 code unit.

**Special JS Features or Syntax**

Neither test case uses any special JavaScript features or syntax beyond the basic `for` loop and the `String.fromCharCode.apply()` method.

**Pros and Cons of Each Approach**

1. **For-loop**:
	* Pros: Can be optimized using a more efficient algorithm, such as using a single pointer to iterate over the character codes.
	* Cons: May have higher overhead due to the use of a `for` loop, which can lead to slower execution times.
2. **String.fromCharCode.apply()**:
	* Pros: Can be optimized using parallel processing or SIMD instructions to accelerate performance.
	* Cons: May have lower overhead for small input sizes, but can become less efficient as the input size increases.

**Benchmark Results**

The latest benchmark results show that the `String.fromCharCode.apply()` method outperforms the `For-loop` approach by a significant margin ( approximately 50x). This suggests that using `String.fromCharCode.apply()` may be a more efficient way to convert an array of character codes into a string in JavaScript.

**Other Alternatives**

There are other ways to convert an array of character codes into a string in JavaScript, such as:

1. Using the `Array.prototype.map()` method: `chars.map(String.fromCharCode)`
2. Using the `String.fromCharCode` function with a `forEach` loop: `chars.forEach(function(char) { s += String.fromCharCode(char); });`
3. Using a library like `utf-8` or `iconv-lite` to handle character encoding conversions.

However, these alternatives may have their own overhead and performance characteristics that should be considered when choosing the best approach for a specific use case.

Related benchmarks:

String from Charcode test (version: 0)

Comparing performance of: For-loop vs String.fromCharCode.apply

Created: 9 years ago by: Guest

Jump to the latest result

For-loop

String.fromCharCode.apply

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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