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.lenght; i++) { array[i]; }
vor with predefined size
var size = array.lenght 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
vor 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 world of JavaScript microbenchmarks!

**Benchmark Definition JSON**

The provided benchmark definition JSON defines a set of test cases to compare the performance of different loop constructs in JavaScript: `for`, `foreach`, and `some`. The script preparation code initializes an array of size 100, which is used as input for all tests.

**Loop Constructs Comparison**

Here's a brief overview of each loop construct, their pros and cons, and alternative approaches:

1. **For Loop (`for (var i in array) { ... }`)**:
	* Pros: Simple, straightforward, and well-supported by most browsers.
	* Cons: May be slower due to the overhead of iterating over the `array` object's properties.
	* Alternative: Use a traditional `for` loop with an index variable (`for (var i = 0; i < array.length; i++) { ... }`)
2. **Foreach Loop (`array.forEach(function(item, index) { return item; });`)**:
	* Pros: Concise, readable, and efficient since it avoids the need for explicit indexing.
	* Cons: May be slower due to the overhead of function calls and the `forEach` method's implementation.
	* Alternative: Use a traditional `for` loop with an index variable (`for (var i = 0; i < array.length; i++) { ... }`)
3. **Some Loop (`array.some(function(item, index) { return item === array[index]; });`)**:
	* Pros: Simple and concise, but may be slower due to the overhead of function calls.
	* Cons: May not work correctly if the input array is sparse or has holes (i.e., `undefined` values).
	* Alternative: Use a traditional `for` loop with an index variable (`for (var i = 0; i < array.length; i++) { ... }`)
4. **While Loop (`while ((a=array.pop()) !== undefined) { ... }`)**:
	* Pros: Flexible and can be used for more complex logic, but may be slower due to the overhead of function calls.
	* Cons: Can lead to stack overflows if not used carefully.
	* Alternative: Use a traditional `for` loop with an index variable (`for (var i = 0; i < array.length; i++) { ... }`)
5. **Using Array Indexes Directly (`array[i]` or `array[index]`)**:
	* Pros: Simple and efficient, as it avoids the overhead of function calls.
	* Cons: May be slower due to the overhead of accessing array elements directly.

**Library Usage**

The benchmark definition JSON does not explicitly mention any libraries. However, some tests might use built-in JavaScript functions or methods (e.g., `forEach`, `some`) that are part of the language specification.

**Special JS Features and Syntax**

There is no explicit mention of special JS features or syntax in the provided benchmark definition JSON. However, it's worth noting that some features like arrow functions (`=>`) and async/await syntax might be used in the actual JavaScript code being tested.

**Other Alternatives**

If you're looking for alternative approaches to these loop constructs, here are a few options:

* For loops: `while` loops or recursive functions.
* Foreach loops: Traditional `for` loops with an index variable or `filter()` method.
* Some loops: Traditional `for` loops with an index variable or `every()` method.
* While loops: Recursive functions or traditional `for` loops.

Keep in mind that the choice of loop construct ultimately depends on your specific use case, performance requirements, and personal preference.

Latest run results:

Run details: (Test run date: 7 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.98 Safari/537.36

Browser/OS: Chrome 54 on Mac OS X 10.12.1

View result in a separate tab

Test name	Executions per second
for..in	4171367.8 Ops/sec
foreach	749183.2 Ops/sec
some	757456.4 Ops/sec
for	10158299.0 Ops/sec
vor with predefined size	10400390.0 Ops/sec
while	1898146.5 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 vor with predefined size vs while

Created: 7 years ago by: Guest

Jump to the latest result

for..in

foreach

some

for

vor 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):