Benchmark: String reversal 2

Script Preparation code:

let string = Array.from({
    length: 50
}, (_, index) => index).join('')

function* backwards(iterable) {
    for (let {
            length
        } = iterable; length--;) yield iterable[length]
}

Tests:

spread+toReversed+join
for(let i = 300; i--;)var t = [...string].toReversed().join('')
Array.from+toReversed+join
for(let i = 300; i--;)var t = Array.from(string).toReversed().join('')
toReversed.call+join
for(let i = 300; i--;)var t = [].toReversed.call(string).join('')
backwards function*
for(let i = 300; i--;)var t = [...backwards(string)].join('')
Array.of
for(let i = 300; i--;)var t = Array.of(...string).toReversed().join('')
Array
for(let i = 300; i--;)var t = Array(...string).toReversed().join('')

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
spread+toReversed+join
Array.from+toReversed+join
toReversed.call+join
backwards function*
Array.of
Array

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 23 hours ago)

User agent: Mozilla/5.0 (X11; CrOS x86_64 14541.0.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.36

Browser/OS: Chrome 126 on Chrome OS 14541.0.0

View result in a separate tab

Test name	Executions per second
spread+toReversed+join	1117.5 Ops/sec
Array.from+toReversed+join	1149.9 Ops/sec
toReversed.call+join	348.8 Ops/sec
backwards function*	453.6 Ops/sec
Array.of	426.0 Ops/sec
Array	486.2 Ops/sec

Autogenerated LLM Summary (model gpt-4o-mini, generated 19 hours ago):

LLMs can make mistakes. Check important info.

The provided benchmark evaluates various approaches to reversing a string in JavaScript, using a consistent string length of 50 characters created from the integers 0 to 49. The benchmark assesses the performance of six different methods to reverse this string, measuring how many times each method can be executed per second.

### Approaches Compared

1. **Spread Operator + `toReversed()` + `join('')`**
   - **Test Name**: "spread+toReversed+join"
   - **Benchmark Definition**: `for(let i = 300; i--;)var t = [...string].toReversed().join('')`
   - **Execution Performance**: 1117.46 ops/sec
  
2. **`Array.from()` + `toReversed()` + `join('')`**
   - **Test Name**: "Array.from+toReversed+join"
   - **Benchmark Definition**: `for(let i = 300; i--;)var t = Array.from(string).toReversed().join('')`
   - **Execution Performance**: 1149.90 ops/sec

3. **`toReversed.call()` + `join('')`**
   - **Test Name**: "toReversed.call+join"
   - **Benchmark Definition**: `for(let i = 300; i--;)var t = [].toReversed.call(string).join('')`
   - **Execution Performance**: 348.85 ops/sec
  
4. **Backward generator function**
   - **Test Name**: "backwards function*"
   - **Benchmark Definition**: `for(let i = 300; i--;)var t = [...backwards(string)].join('')`
   - **Execution Performance**: 453.55 ops/sec

5. **`Array.of()` + `toReversed()` + `join('')`**
   - **Test Name**: "Array.of"
   - **Benchmark Definition**: `for(let i = 300; i--;)var t = Array.of(...string).toReversed().join('')`
   - **Execution Performance**: 426.03 ops/sec

6. **`Array()` + `toReversed()` + `join('')`**
   - **Test Name**: "Array"
   - **Benchmark Definition**: `for(let i = 300; i--;)var t = Array(...string).toReversed().join('')`
   - **Execution Performance**: 486.21 ops/sec

### Pros and Cons of Different Approaches

1. **Spread Operator + `toReversed()`**
   - **Pros**: 
     - Very readable and concise.
     - Leverages the modern JavaScript feature set, including `toReversed()`.
   - **Cons**: 
     - Can be less performant in certain older environments due to its syntactic sugar.

2. **`Array.from()` + `toReversed()`**
   - **Pros**: 
     - Also succinct, and works well for converting iterable objects.
   - **Cons**: 
     - Slightly slower than the spread operator approach but still performs well.

3. **`toReversed.call()`**
   - **Pros**: 
     - Provides a way to invoke the method directly on the string without conversion.
   - **Cons**: 
     - Poorer performance and more verbose than other methods.

4. **Backward Generator Function**
   - **Pros**: 
     - Demonstrates the use of generator functions, which can yield results one at a time, offering flexibility.
   - **Cons**: 
     - Slower performance and often considered less idiomatic for simple tasks like string reversal.

5. **`Array.of()` + `toReversed()`**
   - **Pros**: 
     - Constructs arrays from multiple values. Visually similar to `Array.from()`.
   - **Cons**: 
     - Appears to have lower performance and uses a method less common than `Array.from()`.

6. **`Array()` + `toReversed()`**
   - **Pros**: 
     - Classic way to create an array from a series of values.
   - **Cons**: 
     - Performance-wise, it isn’t as optimized as the spread operator or `Array.from()` methods.

### Other Considerations

- **Readability**: When coding for maintainability, the approach that is easiest to read (often `Array.from()` or the spread operator) may be more favorable.
- **Browser Compatibility**: The `toReversed()` method is relatively new and may not be supported in older browsers, which is crucial for applications targeting a broad audience.
- **Performance Testing**: The benchmark results indicate the relative performance of these methods in a specific environment (in this case, Chrome 126). Results might differ on other platforms or browsers.

### Alternatives

Other alternative approaches for string reversal could include:
- Manual loop iteration (e.g., using a `for` loop to construct the reversed string).
- Using recursion (though this may have performance and stack depth implications).
- Using traditional methods with `.split('').reverse().join('')`.

Each method has its advantages depending on the use case in terms of performance, readability, and compatibility, and the appropriate method may vary based on context and application requirements.

Related benchmarks:

String reversal 2 (version: 1)

Comparing performance of: spread+toReversed+join vs Array.from+toReversed+join vs toReversed.call+join vs backwards function* vs Array.of vs Array

Created: 23 hours ago by: Guest

Jump to the latest result

spread+toReversed+join

Array.from+toReversed+join

toReversed.call+join

backwards function*

Array.of

Array

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gpt-4o-mini, generated 19 hours ago):