Benchmark: for vs foreach vs some

Script Preparation code:

var array = new Array(100);

Tests:

for..in
for (var i in array) { array[i]; }
foreach
array.forEach(function(item, index) { return item; });
some
array.some(function(item, index) { return item === array[index]; });
for
for (var i = 0; i < array.length; i++) { array[i]; }
for with predefined size
var size = array.length for (var i = 0; i < size; i++) { array[i]; }
while
while((a=array.pop()) !== undefined){ //do your stuff }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for..in
foreach
some
for
for with predefined size
while

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

Let's dive into the explanation of the provided benchmark.

**Benchmark Definition**

The benchmark is designed to compare the performance of three loop iteration methods:

1. `for` (with and without predefined size)
2. `foreach`
3. `some`

These loops are intended to iterate over an array of 100 elements.

**Options Compared**

Here's a brief description of each option:

* **For**: A traditional loop that iterates over the array using a manual index (`var i = 0; i < array.length; i++)`.
* **Foreach**: A loop that uses the `forEach` method to iterate over the array, where each element is executed in sequence.
* **Some**: A loop that uses the `some` method to iterate over the array and returns `true` if any element matches a condition. However, since we're not checking for anything specific, this loop essentially iterates over the entire array.
* **For with predefined size**: Similar to the traditional `for`, but with the array length precomputed (`var size = array.length;`).
* **While**: A loop that uses a while loop to iterate over the array, where each element is executed until it reaches the end of the array.

**Pros and Cons**

Here's a brief summary:

* **For**: Simple and efficient, but can be verbose. Requires manual index management.
* **Foreach**: Easy to use and concise, but can be slower due to overhead from method call.
* **Some**: Slowest option due to unnecessary iteration over the entire array. Useless for this benchmark since we're not checking for anything specific.
* **For with predefined size**: Similar performance to traditional `for`, but with less code duplication.
* **While**: Less readable and more prone to errors compared to traditional loops.

**Library: Lodash**

The `some` method is part of the popular JavaScript library Lodash. Lodash provides a set of useful functions for tasks like array manipulation, object iteration, and more.

**Special JS Feature/Syntax**

None mentioned in this benchmark.

**Other Alternatives**

For loop iterations:

* Using `for...of`: Similar to traditional `for`, but with a more concise syntax.
* Using `for (let i = 0; i < array.length; i++)`: Similar to traditional `for`, but with let instead of var.

The `foreach` method can also be implemented using `map()`:

```javascript
array.forEach((item) => {
    // do something
});
```

While loops are generally less common in JavaScript due to the availability of other loop constructs. However, they can still be useful for specific use cases or when working with legacy code.

Overall, this benchmark provides a useful comparison of different loop iteration methods and highlights the trade-offs between simplicity, readability, and performance.

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/106.0.0.0 Safari/537.36

Browser/OS: Chrome 106 on Windows

View result in a separate tab

Test name	Executions per second
for..in	3936548.8 Ops/sec
foreach	5299783.5 Ops/sec
some	4866960.0 Ops/sec
for	85166.4 Ops/sec
for with predefined size	194586.6 Ops/sec
while	3624928.5 Ops/sec

Related benchmarks:

for vs foreach vs some (version: 0)

Compare loop performance

Comparing performance of: for..in vs foreach vs some vs for vs for with predefined size vs while

Created: 7 years ago by: Guest

Jump to the latest result

for..in

foreach

some

for

for with predefined size

while

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):