Benchmark: Find index in string with recursion vs findIndex

Script Preparation code:

var sampleString = 'abcdefghijklmnopqrstuvwxyz';

var recurseFindIndex = (charArray, i = 0) => {
  const [curr, ...rest] = charArray;
  if (curr === 'z') return i;
  else return recurseFindIndex(rest, i + 1);
};

Tests:

findIndex
sampleString.split('').findIndex(char => char === 'z');
Recursion
recurseFindIndex(sampleString);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
findIndex
Recursion

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 16_3 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/111.0.5563.72 Mobile/15E148 Safari/604.1

Browser/OS: Chrome Mobile iOS 111 on iOS 16.3

View result in a separate tab

Test name	Executions per second
findIndex	2777001.5 Ops/sec
Recursion	163935.2 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark test.

**Benchmark Definition**

The benchmark is designed to compare two approaches for finding the index of a character within a string:

1. `split('').findIndex(char => char === 'z')`: This approach uses the `split` method to convert the string into an array of characters, and then calls the `findIndex` method on that array. The callback function passed to `findIndex` checks if each character is equal to `'z'`.
2. `recurseFindIndex(sampleString)`: This approach is a custom recursive function defined in the JavaScript code. It iterates through the string character by character, checking if the current character is equal to `'z'`. If it finds a match, it returns the index; otherwise, it recursively calls itself on the remaining characters.

**Options Compared**

The two approaches are compared, with the first one being the built-in `split` and `findIndex` method, and the second one being the custom recursive function. The test is likely trying to determine which approach is faster for finding a specific character within a string.

**Pros and Cons of Each Approach**

1. **Built-in `split` and `findIndex` method**:
	* Pros: Fast, efficient, and widely supported.
	* Cons: May be slower for very large strings or performance-critical applications due to the overhead of creating an array from the string.
2. **Custom Recursive Function (`recurseFindIndex`)**:
	* Pros: Can be more flexible and adaptable to specific use cases, as it allows for manual control over iteration and character checking.
	* Cons: Typically slower than built-in methods, especially for large strings or performance-critical applications, due to the overhead of recursive function calls.

**Library/Functionality Used**

The `split` method is a standard JavaScript method that converts a string into an array of elements. The `findIndex` method is also a standard JavaScript method that returns the index of the first element in the array that satisfies the provided condition.

**Special JS Feature/Syntax**

There doesn't appear to be any special JavaScript features or syntax used in this benchmark.

**Other Alternatives**

If you wanted to test alternative approaches, some possible options could include:

1. Using `indexOf` instead of `findIndex`, which would iterate through the string until finding a match and then return the index.
2. Using a loop to iterate through the characters in the string, without using any built-in methods like `split` or `findIndex`.
3. Using a more advanced string searching algorithm, such as Boyer-Moore or Knuth-Morris-Pratt.

Keep in mind that these alternatives might not be suitable for this specific benchmark, which is focused on comparing two simple approaches with built-in JavaScript methods.

Related benchmarks:

Find index in string with recursion vs findIndex (version: 0)

What's faster to locate a character's index within a string, findIndex or recursion?

Comparing performance of: findIndex vs Recursion

Created: one year ago by: Guest

Jump to the latest result

findIndex

Recursion

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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