Benchmark: Javascript: reduce VS for (modified)

Javascript: reduce VS for (modified) (version: 0)

Compare the "reduce" method with the "for" iteration method. Use case: There is an array with different numbers, we will compare the performance between the two methods to find the quantity of numbers greater than zero in the array list.

Comparing performance of: Number 1: use for iterator vs Number 2: using reduce method

Created: 4 years ago by: Registered User

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Script Preparation code:

var list = [1, 0, -2, -1, 3, 0, 1, 8, -10, 3, 0, -1, -3];

Tests:

Number 1: use for iterator
let countNumberGreaterThanZero = 0; const listLength = list.length; for (let i = 0; i < listLength; i++) { if (list[i] > 0) { countNumberGreaterThanZero++; } }
Number 2: using reduce method
let countsNumbersGreaterThanZero = (acc, cur) => acc + (cur > 0 ? 1 : 0); list.reduce(countsNumbersGreaterThanZero, 0)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Number 1: use for iterator
Number 2: using reduce method

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/14.0 Safari/605.1.15

Browser/OS: Safari 14 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Number 1: use for iterator	745834.9 Ops/sec
Number 2: using reduce method	7007154.5 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 and explain what's being tested, compared, and their pros and cons.

**Benchmark Definition**

The benchmark compares two methods to find the quantity of numbers greater than zero in an array:

1. **`for` iteration method**: A traditional loop-based approach using a `for` loop to iterate through the array elements.
2. **`reduce` method**: An array reduction method that applies a callback function to each element, accumulating a result.

**Script Preparation Code**

The script defines an array `list` with various numbers:
```javascript
var list = [1, 0, -2, -1, 3, 0, 1, 8, -10, 3, 0, -1, -3];
```
This is the input data used for both testing methods.

**Individual Test Cases**

There are two test cases:

### Test Case 1: `Number 1: use for iterator`

The benchmark definition code for this test case uses a traditional `for` loop to iterate through the array elements:
```javascript
let countNumberGreaterThanZero = 0;
const listLength = list.length;

for (let i = 0; i < listLength; i++) {
  if (list[i] > 0) {
    countNumberGreaterThanZero++;
  }
}
```
This implementation uses a simple loop to iterate through the array elements, incrementing a counter for each element greater than zero.

### Test Case 2: `Number 2: using reduce method`

The benchmark definition code for this test case uses the `reduce` method with a callback function:
```javascript
let countsNumbersGreaterThanZero = (acc, cur) => acc + (cur > 0 ? 1 : 0);

list.reduce(countsNumbersGreaterThanZero, 0);
```
This implementation uses the `reduce` method to apply the callback function to each element in the array. The callback function increments an accumulator value (`countsNumbersGreaterThanZero`) for each element greater than zero.

**Pros and Cons of Each Approach**

* **`for` iteration method**:
	+ Pros: Simple, easy to understand, and well-supported by most browsers.
	+ Cons: Can be slower due to the overhead of loop control.
* **`reduce` method**:
	+ Pros: Efficient, concise, and can be faster than traditional loops for large datasets.
	+ Cons: Less intuitive for beginners, may require more memory.

**Library and Special JS Feature**

There is no library used in this benchmark. However, the `reduce` method is a built-in JavaScript method that is supported by most modern browsers.

**Other Considerations**

* **Browser support**: The benchmark measures performance across different browsers (Safari 14) on a desktop platform.
* **Performance**: The benchmark focuses on measuring the execution speed of both testing methods.

**Alternatives**

If you want to compare other approaches or libraries, you can consider:

* Using other array reduction methods like `forEach`, `map`, or `filter`.
* Implementing custom loop-free algorithms using recursion or closures.
* Comparing performance with different data structures, such as arrays vs. linked lists.

Keep in mind that this benchmark is focused on comparing two specific testing methods and may not be representative of all JavaScript scenarios.

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