Benchmark: Array access VS substring

Script Preparation code:

var s = "hello";

Tests:

Array access
var c = s[0];
substring
var c = s.substring(0, 1);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array access
substring

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):

LLMs can make mistakes. Check important info.

Let's break down the provided JSON and benchmark preparation code to understand what is being tested.

**Benchmark Definition**

The provided JSON represents a JavaScript microbenchmark, where users can create and run tests to compare different approaches. In this case, we have a single benchmark definition with two test cases:

*   "Array access"
*   "substring"

These test cases are designed to measure the performance difference between accessing an element of an array using square brackets (`s[0]`) and using the `substring` method (`s.substring(0, 1)`).

**Options Compared**

Two options are being compared in this benchmark:

1.  **Array Access (using square brackets)**: This approach uses the bracket notation to access a specific element of an array.
2.  **Substring Method**: This approach uses the `substring` method to extract a substring from the original string.

**Pros and Cons of Each Approach**

*   **Array Access**:
    *   **Pros**:
        *   Efficient for large arrays, as it avoids creating intermediate strings or using memory allocation.
        *   Can be faster due to direct access to the array element.
    *   **Cons**:
        *   May not be as readable or intuitive for developers who are not familiar with bracket notation.
        *   Can lead to errors if the array index is out of bounds.
*   **Substring Method**:
    *   **Pros**:
        *   More readable and intuitive, especially for developers who are familiar with string manipulation methods.
        *   Easier to handle edge cases, such as extracting a substring from an empty or null string.
    *   **Cons**:
        *   May be slower due to the creation of intermediate strings and potential memory allocation overhead.
        *   Can lead to performance issues if used extensively.

**Library**

In this benchmark, no specific library is required. The `substring` method is a built-in JavaScript function that can be used without any external dependencies.

**Special JS Feature or Syntax**

There are no special JavaScript features or syntax being tested in this benchmark. The code is straightforward and follows standard JavaScript syntax.

**Other Alternatives**

If you're interested in exploring alternative approaches, here are some options:

*   **Array Splice**: Instead of using array access (`s[0]`), you could use the `splice` method to remove the first element from the string.
*   **String Indexing**: You could also use string indexing (`'hello'[0]`) as an alternative approach.

Keep in mind that these alternatives might have different performance characteristics or readability implications compared to the original approaches.

Latest run results:

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

User agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:101.0) Gecko/20100101 Firefox/101.0

Browser/OS: Firefox 101 on Ubuntu

View result in a separate tab

Test name	Executions per second
Array access	819796224.0 Ops/sec
substring	138376832.0 Ops/sec

Related benchmarks:

Array access VS substring (version: 0)

Comparing performance of: Array access vs substring

Created: 2 years ago by: Guest

Jump to the latest result

Array access

substring

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):