Benchmark: split vs loop - MeasureThat.net

Tests:

split
'abcdefghijklmnopqrstuvwxyz'.split().reverse().join('')
loop
let s = 'abcdefghijklmnopqrstuvwxyz'; let r = ''; for (let i = s.length -1; i<=0; i--) { r+=s[i] }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
split
loop

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 5 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3578.98 Safari/537.36

Browser/OS: Chrome 71 on Mac OS X 10.12.6

View result in a separate tab

Test name	Executions per second
split	24325982.0 Ops/sec
loop	917969600.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

The provided benchmark comparison tests two approaches for reversing a string: using the `split()` method followed by `reverse()` and `join()`, and using a simple loop.

**Options Compared:**

1. **`split().reverse().join('')`**: This approach uses the `split()` method to split the input string into an array of characters, reverses the array using `reverse()`, and then joins it back into a single string using `join('')`. The `split()` method is used with an empty separator (`''`) to split the string at each character.
2. **`for...loop`**: This approach uses a traditional `for` loop to iterate over the characters of the input string in reverse order, appending each character to a new string `r`.

**Pros and Cons:**

1. **`split().reverse().join('')`**:
	* Pros:
		+ Concise and elegant syntax.
		+ Can be faster for very large strings due to optimized internal implementations of `Array.prototype.reverse()` and `String.prototype.join()`.
	* Cons:
		+ May incur additional overhead due to the creation of an intermediate array.
		+ Requires a string to be passed as input, which might not always be available (e.g., if you only have access to an array of characters).
2. **`for...loop`**:
	* Pros:
		+ Directly manipulates strings without creating any intermediate data structures.
		+ Flexible and easy to understand for those familiar with traditional loop constructs.
	* Cons:
		+ Can be slower for very large strings due to the overhead of manually iterating over each character.

In general, the `split().reverse().join('')` approach is a good choice when:

* You have access to an array or other data structure that can be easily split and reversed.
* The input string is relatively small or medium-sized.

On the other hand, the `for...loop` approach might be preferred when:

* You need to manipulate strings without creating intermediate data structures.
* The input string is very large and you want to avoid potential overhead of array operations.

**Library Usage:**

In this benchmark, neither test case explicitly uses any external libraries. However, it's worth noting that the `Array.prototype.reverse()` method is a part of the ECMAScript standard, which means it's implemented by most modern JavaScript engines without requiring any additional library dependencies.

**Special JS Features/Syntax:**

There are no special JavaScript features or syntax used in this benchmark that would require prior knowledge or understanding. The code snippets are straightforward and easy to understand for software engineers with a basic understanding of JavaScript basics.

**Alternatives:**

If you're looking for alternative approaches to reversing strings, here are a few options:

1. **Using `Array.prototype.reduce()`**: Instead of using `reverse()`, you can use `reduce()` to build the reversed string from an array of characters.
```javascript
let s = 'abcdefghijklmnopqrstuvwxyz';
let r = [];
for (let c of s) {
  r.push(c);
}
r.reverse();
console.log(r.join('')); // "zyxwvutsrqponmlkjihgfedcba"
```
2. **Using `Array.prototype.every()` and `String.prototype.split()```**: This approach uses `every()` to iterate over each character in the input string, which is then split into an array using `split()`. The reversed array can then be joined back into a single string.
```javascript
let s = 'abcdefghijklmnopqrstuvwxyz';
let r = '';
for (let c of Array.from(s).reverse()) {
  r += c;
}
console.log(r); // "zyxwvutsrqponmlkjihgfedcba"
```
Keep in mind that these alternative approaches might have different performance characteristics compared to the original `split().reverse().join('')` and `for...loop` implementations.

Related benchmarks:

split vs loop (version: 0)

Comparing performance of: split vs loop

Created: 5 years ago by: Guest

Jump to the latest result

split

loop

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):