Benchmark: String.split with limit 4

Script Preparation code:

var a = 'a'.repeat(100);

Tests:

split without limit
a.split('').slice(40, 50);
split with limit
a.split('', 50).slice(40, 50);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
split without limit
split with limit

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:93.0) Gecko/20100101 Firefox/93.0

Browser/OS: Firefox 93 on Windows

View result in a separate tab

Test name	Executions per second
split without limit	2712620.8 Ops/sec
split with limit	3362028.5 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down what's being tested in the provided JSON benchmark.

**Benchmark Definition**

The first part of the benchmark, represented by the `Script Preparation Code` and `Html Preparation Code`, defines a basic JavaScript microbenchmark:

```javascript
var a = 'a'.repeat(100);
```

This code creates a string `a` consisting of 100 consecutive occurrences of the character `'a'`. The purpose of this string is likely to provide a large enough input for the subsequent benchmark.

**Options Compared**

Two test cases are being compared:

1. **Split without limit (`split without limit`)**
   ```javascript
a.split('').slice(40, 50);
```

This code splits the string `a` into individual characters using `split('')`, and then uses `slice(40, 50)` to extract a slice of 10 characters starting from the 41st character (since indexing starts at 0). The pros of this approach are that it's simple to implement and can be efficient for very large strings.

However, there might be performance issues if the number of iterations is high because `slice()` has to iterate over a significant portion of the string for any given index above 40. This means that for every character after the first 40 characters, the function will need to allocate and free more memory each time it's called.

2. **Split with limit (`split with limit`)**
   ```javascript
a.split('', 50).slice(40, 50);
```

Similar to the first option, this code splits `a` into individual characters using `split('')`, but it adds an additional parameter of 50 for the maximum number of items to return. This helps prevent excessive memory allocation by limiting the slice.

The cons are that using a limit might impact performance due to repeated calls to `slice()` with different indexes, as well as slightly slower execution times on very large strings compared to splitting without limits and then slicing later in the operation (the first case).

**Libraries**

None of the provided benchmark code snippet uses any libraries.

**Special JS Features or Syntax**

The use of template literals like `"a".repeat(100);` is a modern JavaScript feature introduced in ECMAScript 2015, also known as ES6. It's used to create new strings with values interpolated inside them.

However, without more context about other test cases, it's difficult to make broad assessments of its impact on overall benchmark performance.

Related benchmarks:

String.split with limit 4 (version: 0)

Comparing performance of: split without limit vs split with limit

Created: 3 years ago by: Guest

Jump to the latest result

split without limit

split with limit

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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