Benchmark: 1134112 - MeasureThat.net

Tests:

1
const max = 5; const arr = [1, 0, () => {}, '', {}]; const fArr = Array.from({ length: max }, (_, i) => arr[i]); const nArr = fArr.filter(Boolean);
2
const max = 5; const arr = [1, 0, () => {}, '', {}]; const fArr = []; const nArr = []; for (let i = 0; i < max; i += 1) { const el = arr[i]; fArr.push(el); if (el) nArr.push(el); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
1
2

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:127.0) Gecko/20100101 Firefox/127.0

Browser/OS: Firefox 127 on Mac OS X 10.15

View result in a separate tab

Test name	Executions per second
1	8813060.0 Ops/sec
2	36502480.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Measuring JavaScript performance is crucial for optimizing code and ensuring smooth user experiences.

The provided JSON represents two test cases, each with its own benchmark definition. Let's break down what's being tested in each case:

**Test Case 1**

In this test case, the script preparation code consists of:
```javascript
const max = 5;
const arr = [1, 0, () => {}, '', {}];
const fArr = Array.from({ length: max }, (_, i) => arr[i]);
const nArr = fArr.filter(Boolean);
```
Here, we have an array `arr` with a mix of values, including numbers, zeros, empty strings, and a function. We then create a new array `fArr` by using the spread operator to duplicate the elements from `arr`. Finally, we filter out any falsy values from `fArr` to get `nArr`.

The test is comparing the performance of creating `nArr` using two different approaches:

**Approach 1: Using Array.from()**

```javascript
const fArr = Array.from({ length: max }, (_, i) => arr[i]);
```
This approach creates a new array by duplicating each element from `arr`. The `Array.from()` method takes an object with a `length` property and calls the provided callback function for each index.

**Approach 2: Using a traditional loop**

```javascript
const fArr = [];
for (let i = 0; i < max; i += 1) {
  const el = arr[i];
  fArr.push(el);
  if (el) nArr.push(el);
}
```
This approach uses a traditional `for` loop to push elements from `arr` into a new array `fArr`. If the element is truthy, it's also pushed into `nArr`.

**Pros and Cons:**

* **Approach 1 (Array.from()):**
	+ Pros:
		- More concise and expressive code.
		- Less prone to errors due to its simplicity.
	+ Cons:
		- May be slower for very large arrays, as it creates a new array with all elements.
* **Approach 2 (Traditional loop):**
	+ Pros:
		- Can be faster for very large arrays, as it only creates an array with the filtered elements.
	+ Cons:
		- More verbose and error-prone code.

**Test Case 2**

This test case is similar to Test Case 1, but instead of using `Array.from()`, it uses a traditional loop to create `fArr`:
```javascript
const fArr = [];
for (let i = 0; i < max; i += 1) {
  const el = arr[i];
  fArr.push(el);
  if (el) nArr.push(el);
}
```
The only difference between this test case and Test Case 1 is the approach used to create `fArr`.

**Library usage**

Neither of these tests cases uses any external libraries.

**Special JavaScript features**

None.

Now, let's consider other alternatives for creating `nArr`:

* Using a library like Lodash: You can use Lodash's `repeat()` and `filter()` functions to achieve the same result:
```javascript
const _ = require('lodash');
const nArr = _.repeat(arr, max).filter(Boolean);
```
This approach uses Lodash's utility function `repeat()` to create an array with repeated elements from `arr`, and then filters out any falsy values using `filter()`.
* Using a custom implementation: You can write your own custom function to create `nArr` using iteration:
```javascript
function repeatArray(arr, max) {
  const nArr = [];
  for (let i = 0; i < max; i++) {
    nArr.push(arr[i]);
  }
  return nArr.filter(Boolean);
}
const nArr = repeatArray(arr, max);
```
This approach uses a custom function `repeatArray()` to create the array with repeated elements from `arr`, and then filters out any falsy values using the `filter()` method.

These alternatives can be useful in specific scenarios, but they may introduce additional overhead or complexity compared to the original approaches.

Related benchmarks:

1134112 (version: 0)

Comparing performance of: 1 vs 2

Created: one year ago by: Guest

Jump to the latest result

1

2

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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