Benchmark: String.split with limit 3

Script Preparation code:

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

Tests:

split without limit
a.split('').slice(30, 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 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/94.0.4606.61 Safari/537.36

Browser/OS: Chrome 94 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
split without limit	2376932.0 Ops/sec
split with limit	3391328.2 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON benchmark definition and test cases.

**Benchmark Definition:**

The provided JSON defines a JavaScript microbenchmark for testing the performance of `String.split()` with different limits.

Here, `String.split()` is a built-in JavaScript method that splits a string into an array of substrings using a specified separator. The two test cases being compared are:

1.  **`a.split('').slice(30, 50);`**: This test case calls `split()` on the string `'a'.repeat(100)`, which creates a long string consisting of 'a' repeated 100 times. It then slices this array to get substrings between index 30 and 50.
2.  **`a.split('', 50).slice(40, 50);`**: This test case calls `split()` on the same string `'a'.repeat(100)`, but with a limit of 50. This effectively splits the string into an array of substrings using only the first character 'a' as the separator. It then slices this array to get substrings between index 40 and 50.

**Options Compared:**

The two test cases are comparing different approaches to split strings:

*   **No limit**: The first test case, `a.split('').slice(30, 50);`, splits the string without a specified limit. This approach can be faster if the string is large and doesn't fit in memory, as it avoids creating an intermediate array.
*   **Limited split**: The second test case, `a.split('', 50).slice(40, 50);`, splits the string with a specified limit of 50. This approach creates an intermediate array if the original string doesn't fit in memory and then slices that array.

**Pros and Cons:**

*   **No Limit (split without limit)**:
    *   Pros:
        *   Can be faster for large strings as it avoids creating an intermediate array.
        *   May reduce memory usage.
    *   Cons:
        *   Can be slower due to potential string copying or garbage collection overhead.
*   **Limited Split**:
    *   Pros:
        *   Typically more efficient than the no limit approach, especially for smaller strings.
        *   Ensures consistent performance regardless of string length.
    *   Cons:
        *   May create an intermediate array if the original string is large, leading to increased memory usage.

**Library and Purpose:**

None are explicitly mentioned in this benchmark. However, some JavaScript libraries might implement their own `split()` or similar methods that could potentially affect performance in different ways.

**Special JS Features/Syntax:**

There's no special JavaScript feature or syntax used in these test cases. They only utilize the built-in `String.split()` method and basic arithmetic operations (`slice()`, `repeat()`).

**Alternatives:**

If you need to optimize string splitting, consider using libraries like:

1.  **`lodash.string.prototype.split()`**: Provides an implementation of `split()` with various options for better performance and flexibility.
2.  **`String.prototype.split()` with a custom separator or regex pattern**: Using the built-in `split()` method with a custom separator or regex pattern can offer improved performance for certain use cases.

For general string manipulation, consider using libraries like:

1.  **`lodash.js`**: Offers various utility functions, including those for working with strings.
2.  **`string-parsing` library**: Provides efficient methods for parsing and manipulating strings.

When optimizing string splitting or manipulation in JavaScript, always profile your code to identify performance bottlenecks and consider using optimized libraries or custom implementations tailored to your specific use case.

Related benchmarks:

String.split with limit 3 (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):