Benchmark: Repeating String

Tests:

Simple for loop
function repeatify(string, repetitions) { if (repetitions < 0 || repetitions === Infinity) { throw new RangeError('Invalid repetitions number'); } let result = ''; for (let i = 0; i < repetitions; i++) { result += string; } return result; } repeatify('*', 10000);
Extended for loop
function repeatify2(string, repetitions) { if (repetitions < 0 || repetitions === Infinity) { throw new RangeError('Invalid repetitions number'); } const isEven = repetitions % 2 === 0; const iterations = Math.floor(repetitions / 2); const stringTwice = string + string; let result = ''; for (let i = 0; i < iterations; i++) { result += stringTwice; } if (!isEven) { result += string; } return result; } repeatify2('*', 10000);
Log based
function repeatify3(string, repetitions) { if (repetitions < 0 || repetitions === Infinity) { throw new RangeError('Invalid repetitions number'); } const cache = new Map(); function repeat(string, repetitions) { if (repetitions === 0) { return ''; } const log = Math.floor(Math.log2(repetitions)); let result; if (cache.has(log)) { result = cache.get(log); } else { result = string; for (let i = 1; i <= log; i++) { result += result; cache.set(i, result); } } const repetitionsProcessed = Math.pow(2, log); const repetitionsLeft = repetitions - repetitionsProcessed; return result + repeat(string, repetitionsLeft); } return repeat(string, repetitions); } repeatify3('*', 10000);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Simple for loop
Extended for loop
Log based

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks and analyze the provided benchmark definitions.

**Benchmark Definition**
The benchmark definition is a JSON object that contains information about the test case, including the name, description, script preparation code, and HTML preparation code. In this case, there are three benchmark definitions:

1. "Simple for loop"
2. "Extended for loop"
3. "Log based"

**Test Cases**

Each test case represents a specific implementation of the repeating string function, which takes two arguments: `string` and `repetitions`. The function is expected to return a new string by repeating the original `string` a specified number of times.

### 1. "Simple for loop"

This test case uses a traditional `for` loop to repeat the string.
```javascript
function repeatify(string, repetitions) {
  if (repetitions < 0 || repetitions === Infinity) {
    throw new RangeError('Invalid repetitions number');
  }
  let result = '';
  for (let i = 0; i < repetitions; i++) {
    result += string;
  }
  return result;
}
```
**Pros:**

* Simple and easy to understand
* No additional data structures or complex logic required

**Cons:**

* May be slower due to the overhead of the loop
* Can lead to repeated calculations if the number of repetitions is large

### 2. "Extended for loop"

This test case uses a similar `for` loop, but with an added twist. It checks if the number of repetitions is even and adds an extra repetition of the string if it's not.
```javascript
function repeatify2(string, repetitions) {
  if (repetitions < 0 || repetitions === Infinity) {
    throw new RangeError('Invalid repetitions number');
  }
  const isEven = repetitions % 2 === 0;
  const iterations = Math.floor(repetitions / 2);
  const stringTwice = string + string;
  let result = '';
  for (let i = 0; i < iterations; i++) {
    result += stringTwice;
  }
  if (!isEven) {
    result += string;
  }
  return result;
}
```
**Pros:**

* May be faster than the simple loop due to reduced repeated calculations
* Adds a small optimization by using the `stringTwice` variable

**Cons:**

* Introduces additional logic and data structures (the `isEven` flag and `iterations` variable)
* Can lead to more complex loop iterations

### 3. "Log based"

This test case uses a logarithmic approach to repeat the string.
```javascript
function repeatify3(string, repetitions) {
  if (repetitions < 0 || repetitions === Infinity) {
    throw new RangeError('Invalid repetitions number');
  }
  const cache = new Map();
  function repeat(string, repetitions) {
    if (repetitions === 0) {
      return '';
    }
    const log = Math.floor(Math.log2(repetitions));
    let result;
    if (cache.has(log)) {
      result = cache.get(log);
    } else {
      result = string;
      for (let i = 1; i <= log; i++) {
        result += result;
        cache.set(i, result);
      }
    }
    const repetitionsProcessed = Math.pow(2, log);
    const repetitionsLeft = repetitions - repetitionsProcessed;
    return result + repeat(string, repetitionsLeft);
  }
  return repeat(string, repetitions);
}
```
**Pros:**

* May be the fastest approach due to optimized loop iterations
* Reduces repeated calculations by using a cache

**Cons:**

* Introduces additional data structures (the `cache` map) and complex logic
* Can lead to increased memory usage

In summary, each test case has its pros and cons. The "Log based" approach is likely the fastest due to optimized loop iterations, but it introduces additional complexity and data structures. The "Extended for loop" adds a small optimization by using the `stringTwice` variable, but may lead to increased complexity. The "Simple for loop" is straightforward but may be slower due to repeated calculations.

**Browser Results**
The provided browser results show that:

* The "Log based" approach has the highest executions per second (16449.408203125)
* The "Extended for loop" has a moderate number of executions per second (32179.84375)
* The "Simple for loop" has the lowest number of executions per second (16449.408203125)

These results suggest that the "Log based" approach is indeed the fastest, but further testing and optimization may be necessary to achieve optimal performance.

Latest run results:

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

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 15_3_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/15.3 Mobile/15E148 Safari/604.1

Browser/OS: Mobile Safari 15 on iOS 15.3.1

View result in a separate tab

Test name	Executions per second
Simple for loop	16449.4 Ops/sec
Extended for loop	32179.8 Ops/sec
Log based	409961.4 Ops/sec

Related benchmarks:

Repeating String (version: 0)

Comparing performance of: Simple for loop vs Extended for loop vs Log based

Created: 7 years ago by: Guest

Jump to the latest result

Simple for loop

Extended for loop

Log based

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):