Benchmark: for vs foreach vs some vs for..of 1000 v0

Script Preparation code:

var array = new Array(1000);

Tests:

foreach
array.forEach(function(i) { array[i]; });
for
for (var i = 0; i < array.length; i++) { array[i]; }
for 2
var length = array.length; for (var i = 0; i < length; i++) { array[i]; }
for..of
for (var i of array) { array[i]; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
foreach
for
for 2
for..of

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):

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Let's dive into the world of JavaScript microbenchmarks.

**Benchmark Definition**
The benchmark is designed to compare the performance of different loop constructs in JavaScript:

* `for`
* `foreach` (implemented using an arrow function)
* `some` (not used, likely a leftover from previous versions)
* `for..of`

**Script Preparation Code**
The script creates an array with 1000 elements: `var array = new Array(1000);`. This array is used as the data structure for the benchmark.

**Options Compared**
The benchmark compares the performance of four loop constructs:

1. **Traditional `for` loop**: Uses a counter variable to iterate over the array.
2. **Arrow function-based `foreach` loop**: Uses the `forEach` method with an arrow function to iterate over the array.
3. **`for` loop with manual length checking**: Uses a separate variable to store the length of the array and then uses that variable as the counter.
4. **`for..of` loop**: Uses the `for...of` loop syntax, which is a more modern and concise way to iterate over arrays.

**Pros and Cons**

* Traditional `for` loop:
	+ Simple and easy to understand
	+ Performance can be slower due to the overhead of incrementing a counter variable
* Arrow function-based `foreach` loop:
	+ More concise and easier to write than traditional `for` loops
	+ May have performance advantages due to the use of optimized `forEach` method
* `for` loop with manual length checking:
	+ Can be slower than using a built-in array method like `length`
	+ Requires more code to implement, which can lead to errors
* `for..of` loop:
	+ More concise and easier to write than traditional `for` loops
	+ Performance is generally good due to optimized iteration logic

**Library**
The `forEach` method uses the Array prototype's built-in implementation. This method iterates over an array using a callback function, which is executed for each element in the array.

**Special JS Feature/Syntax**
None of the benchmark options use any special JavaScript features or syntax beyond the standard language features mentioned above.

**Other Alternatives**

If you wanted to add more loop constructs to the benchmark, some alternatives could include:

* `while` loops
* `do...while` loops
* Looping over arrays using `map`, `filter`, or `reduce`
* Using a library like Lodash's `iteratee` function

However, these alternatives would likely require significant changes to the benchmark code and might not provide meaningful comparisons with the original options.

Related benchmarks:

for vs foreach vs some vs for..of 1000 v0 (version: 0)

Compare loop performance

Comparing performance of: foreach vs for vs for 2 vs for..of

Created: 5 years ago by: Guest

Jump to the latest result

foreach

for

for 2

for..of

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):