Benchmark: for vs foreach vs some vs for..of vs for cached length non empty array actually check

Script Preparation code:

var a = new Array(10000);


for(i=0; i<5000; i++){
    a[i] = ([1e7]+-1e3+-4e3+-8e3+-1e11).replace(/[018]/g, c => (c ^ crypto.getRandomValues(new Uint8Array(1))[0] & 15 >> c / 4).toString(16));
}
a[5000] = 1488;
for(i=5001; i<10000; i++){
    a[i] = ([1e7]+-1e3+-4e3+-8e3+-1e11).replace(/[018]/g, c => (c ^ crypto.getRandomValues(new Uint8Array(1))[0] & 15 >> c / 4).toString(16));
}

Tests:

for
var has1488 = false; for (var i = 0; i < a.length; i++) { if (a[i] === 1488) { has1488 = true; break; } }
for cached length
var has1488 = false; for (var i = 0, l=a.length; i < l; ++i) { if (a[i] === 1488) { has1488 = true; break; } }
some
var has1488 = a.some(function(i) { return i === 1488; });
for..of
var has1488 = false; for (var i of a) { if (i === 1488) { has1488 = true; break; } }
foreach
var has1488 = false; a.forEach(function(i) { if (i === 1488) has1488 = true; });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for
for cached length
some
for..of
foreach

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/14.1 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
for	1255.9 Ops/sec
for cached length	2483.8 Ops/sec
some	38074.0 Ops/sec
for..of	33483.3 Ops/sec
foreach	20075.1 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks and explore what's being tested.

**Benchmark Definition**

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

1. `for` loops
2. `foreach` loops
3. `some` function
4. `for...of` loops

The test case involves creating an array with 10,000 elements and then iterating over it using each of the mentioned loop constructs.

**Options Compared**

Here's a brief overview of each option being compared:

* `for` loops: These are traditional loops that use a counter variable to iterate over the array.
* `foreach` loops: These loops iterate over an array using a custom function or callback.
* `some` function: This is a built-in function that returns `true` if at least one element in an array passes a test (in this case, checking for the presence of the value 1488).
* `for...of` loops: These are modern loops introduced in ECMAScript 2015, which provide a concise way to iterate over arrays using a simple syntax.

**Pros and Cons**

Here's a brief summary of each option's pros and cons:

* `for` loops:
	+ Pros: Simple, widely supported, and easy to understand.
	+ Cons: Can be verbose and less efficient than other options.
* `foreach` loops:
	+ Pros: Provides flexibility in choosing the iteration method, can be more concise than traditional `for` loops.
	+ Cons: May require additional setup or library dependencies.
* `some` function:
	+ Pros: Built-in, easy to use, and optimized for performance.
	+ Cons: Limited control over iteration logic, may not suit all use cases.
* `for...of` loops:
	+ Pros: Concise syntax, modern and efficient.
	+ Cons: May require older JavaScript engines or specific implementations.

**Library and Special JS Features**

In this benchmark, the following libraries are used:

* `crypto`: This is a built-in Node.js library that provides cryptographic functions. It's not essential for understanding the loop constructs being compared.

No special JavaScript features are mentioned in the benchmark definition. However, it's worth noting that the use of `for...of` loops may require support for ECMAScript 2015 or later.

**Other Alternatives**

If you're looking for alternative benchmarks or testing frameworks for JavaScript performance, consider:

* jsPerf: A popular online benchmarking platform specifically designed for comparing JavaScript performance.
* Benchmark.js: A lightweight, easy-to-use library for creating and running microbenchmarks in Node.js.
* V8 Perftools: The official benchmarking tools from the V8 engine used in Google Chrome.

Keep in mind that different benchmarks may focus on specific aspects of JavaScript performance or use unique test cases. Always explore and choose a benchmark that aligns with your needs and goals.

Related benchmarks:

for vs foreach vs some vs for..of vs for cached length non empty array actually check (version: 0)

Compare loop performance

Comparing performance of: for vs for cached length vs some vs for..of vs foreach

Created: 3 years ago by: Guest

Jump to the latest result

for

for cached length

some

for..of

foreach

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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