Benchmark: js slice performance -2

Script Preparation code:

function randomString(e) {    
    e = e || 32;
    var t = "ABCDEFGHJKMNPQRSTWXYZabcdefhijkmnprstwxyz2345678",
    a = t.length,
    n = "";
    for (i = 0; i < e; i++) n += t.charAt(Math.floor(Math.random() * a));
    return n
}
var str1 = randomString(100)
var str2 = randomString(10000)
var str3 = randomString(1000000)

Tests:

slice-1
var result1 = str1.slice(1, 3) var result2 = str1.slice(4, 6) var result3 = str1.slice(7, 10)
slice-2
var result1 = str2.slice(1, 30000) var result2 = str2.slice(28999, 69999) var result3 = str2.slice(67000, 99999)
slice-3
var result1 = str3.slice(1, 30000000) var result2 = str3.slice(28999000, 69999000) var result3 = str3.slice(67000000, 99999000)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
slice-1
slice-2
slice-3

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/121.0.0.0 Safari/537.36 Edg/121.0.0.0

Browser/OS: Chrome 121 on Windows

View result in a separate tab

Test name	Executions per second
slice-1	8036909.0 Ops/sec
slice-2	8361604.5 Ops/sec
slice-3	8615830.0 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 benchmark and its test cases to understand what is being tested.

**Benchmark Definition JSON**

The provided JSON represents a JavaScript microbenchmark created on MeasureThat.net. The benchmark definition provides essential information about the test:

1. **Name**: "js slice performance -2"
2. **Description**: A brief description of the test, which is to show the performance of slicing in JavaScript.
3. **Script Preparation Code**: This section contains a custom JavaScript function `randomString` that generates a random string of a specified length. The code also creates three strings: `str1`, `str2`, and `str3`, each with a different length (100, 10,000, and 1,000,000 characters respectively).
4. **Html Preparation Code**: This section is empty, indicating that no HTML preparation is required for the test.

**Individual Test Cases**

The benchmark consists of three individual test cases:

1. **slice-1**
	* The `Benchmark Definition` specifies three slicing operations:
		+ `var result1 = str1.slice(1, 3)`
		+ `var result2 = str1.slice(4, 6)`
		+ `var result3 = str1.slice(7, 10)`
	* These tests measure the performance of slicing a short string (`str1`) with different start and end indices.
2. **slice-2**
	* The `Benchmark Definition` specifies three slicing operations:
		+ `var result1 = str2.slice(1, 30000)`
		+ `var result2 = str2.slice(28999, 69999)`
		+ `var result3 = str2.slice(67000, 99999)`
	* These tests measure the performance of slicing a medium-length string (`str2`) with different start and end indices.
3. **slice-3**
	* The `Benchmark Definition` specifies three slicing operations:
		+ `var result1 = str3.slice(1, 30000000)`
		+ `var result2 = str3.slice(28999000, 69999000)`
		+ `var result3 = str3.slice(67000000, 99999000)`
	* These tests measure the performance of slicing a long string (`str3`) with different start and end indices.

**Library Usage**

None of the benchmark test cases use any external libraries. The code is self-contained within the provided JavaScript file.

**Special JS Features/Syntax**

There are no special JavaScript features or syntax used in these test cases. The focus is solely on measuring the performance of slicing operations.

**Pros and Cons of Different Approaches**

When it comes to optimizing string slicing, there are a few approaches:

1. **Native String Slicing**: Using the built-in `slice()` method is generally the fastest approach. However, this might not be suitable for very large strings due to memory allocation concerns.
2. **Substring vs. Slice**: In JavaScript, both `substring()` and `slice()` can be used for slicing. While they share similar syntax, `slice()` is slightly faster in most cases.
3. **Array.prototype.slice.call()**: This approach uses the `call()` method to call the `slice()` function on an array-like object (in this case, a string). This method can be slower than native string slicing due to the overhead of calling a function.

**Other Alternatives**

If you're looking for alternative ways to measure performance, consider using:

1. **Benchmarking libraries**: Tools like Benchmark.js or Micro-benchmark provide more comprehensive benchmarking capabilities.
2. **Web performance testing frameworks**: Frameworks like WebPageTest or Lighthouse offer in-depth performance analysis and optimization tools.

Keep in mind that the choice of alternative depends on your specific use case, performance requirements, and desired level of complexity.

Related benchmarks:

js slice performance -2 (version: 0)

show slice performance

Comparing performance of: slice-1 vs slice-2 vs slice-3

Created: 3 years ago by: Registered User

Jump to the latest result

slice-1

slice-2

slice-3

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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