Benchmark: generator check speed 2

Script Preparation code:

var a = []
for (var i=0;i<100;i++) a.push({id:i,bool:i%2==1});

Tests:

default
var x = []; for (var elid in a){ if (a[elid].bool){ x.push(a[elid]); } }
generator
var x = a.filter(el=>el.bool)
of
var x = []; for (var el of a){ if (el.bool){ x.push(el); } }
el var default
var x = [],el; for (var elid in a){ el = a[elid]; if (el.bool){ x.push(el); } }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
default
generator
of
el var default

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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

LLMs can make mistakes. Check important info.

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

**Benchmark Definition**

The provided JSON represents a benchmark definition for measuring the performance of iterating over an array to filter out elements based on their `bool` property. The script preparation code defines an array `a` with 100 elements, each containing an `id` and a `bool` value. The `Html Preparation Code` is empty, indicating that no HTML code is required for this benchmark.

**Script Preparation Code**

The script preparation code generates the `a` array:
```javascript
var a = [];
for (var i = 0; i < 100; i++) {
  a.push({ id: i, bool: i % 2 === 1 });
}
```
This creates an array with 100 elements, where each element has an `id` property and a `bool` property. The value of `bool` is determined by the modulus operator (`%`) applied to the `i` index.

**Iteration Methods**

The benchmark defines four different iteration methods:

1. **Default (for...in)**:
```javascript
var x = [];
for (var elid in a) {
  if (a[elid].bool) {
    x.push(a[elid]);
  }
}
```
This method uses the `for...in` loop to iterate over the array, checking each element's `bool` property.

2. **Generator**:
```javascript
var x = a.filter(el => el.bool);
```
This method uses the `filter()` function to create a new array with elements that match the condition `el.bool`.

3. **Of (for...of)**:
```javascript
var x = [];
for (var el of a) {
  if (el.bool) {
    x.push(el);
  }
}
```
This method uses the `for...of` loop to iterate over the array, checking each element's `bool` property.

4. **El var Default**:
```javascript
var x = [];
for (var elid in a) {
  var el = a[elid];
  if (el.bool) {
    x.push(el);
  }
}
```
This method uses the `for...in` loop to iterate over the array, assigning each element to a local variable `el` before checking its `bool` property.

**Library**

In this benchmark, there is no explicit library mentioned. However, the `filter()` function used in the "Generator" iteration method is a built-in JavaScript function.

**Special JS Feature/Syntax**

The benchmark does not explicitly use any special JavaScript features or syntax beyond the standard language. However, it's worth noting that the `for...of` loop and the `filter()` function are part of modern JavaScript and may not be supported in older browsers.

**Pros and Cons of Different Approaches**

Here's a brief summary of each iteration method:

1. **Default (for...in)**:
	* Pros: Simple, widely supported.
	* Cons: Can be slower due to the overhead of the `for...in` loop.
2. **Generator**:
	* Pros: Fast, concise, and expressive.
	* Cons: May not be supported in older browsers or environments that don't support modern JavaScript features.
3. **Of (for...of)**:
	* Pros: Fast, concise, and expressive.
	* Cons: May not be supported in older browsers or environments that don't support modern JavaScript features.
4. **El var Default**:
	* Pros: Simple, widely supported.
	* Cons: Can be slower due to the overhead of the `for...in` loop.

**Other Alternatives**

If you're looking for alternative methods, consider:

1. **Array.prototype.reduce()**: A more functional approach that can be used to filter elements while reducing an array to a single value.
2. **Lodash's _.filter() function**: If you need a more robust filtering solution or want to avoid using the `filter()` method directly.

Keep in mind that the best approach will depend on your specific use case, performance requirements, and the environment you're targeting.

Related benchmarks:

generator check speed 2 (version: 3)

Comparing performance of: default vs generator vs of vs el var default

Created: 6 years ago by: Registered User

Jump to the latest result

default

generator

of

el var default

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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