Benchmark: for tests - MeasureThat.net

Script Preparation code:

var size = 10000;
var arr = [];
for (let i = 0; i < size; i++) {
    arr.push(i);
}

Tests:

forEach
arr.forEach((i) => { console.log(i); });
for
for (let i = 0; i < size; i++) { console.log(arr[i]); }
pre increment for
for (let i = 0; i < size; ++i) { console.log(arr[i]); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
forEach
for
pre increment for

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/99.0.4844.51 Safari/537.36

Browser/OS: Chrome 99 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
forEach	7.5 Ops/sec
for	8.5 Ops/sec
pre increment for	8.3 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark JSON and analyze what is being tested.

**Benchmark Definition**

The benchmark definition specifies that it's called "for tests" with no description. The script preparation code includes two loops: a traditional `for` loop and an incrementing pre-increment `for` loop (not a standard JavaScript feature, but used in some browsers for performance optimization). There is no HTML preparation code.

**Individual Test Cases**

The benchmark has three individual test cases:

1. `forEach`: Verifies the behavior of the `forEach` method on the array.
2. `for`: Tests the traditional `for` loop syntax on the array.
3. `pre increment for`: Examines the performance of an incrementing pre-increment `for` loop (not a standard JavaScript feature).

**Comparison of Options**

The benchmark compares three approaches:

* **Traditional For Loop (`for`)**: A straightforward, non-optimized loop that iterates over the array elements using their indices.
* **Incrementing Pre-Increment `For` Loop (`pre increment for`)**: A custom loop syntax used in some browsers to optimize iteration performance. It increments the loop counter before accessing the current element, which can be faster but also less readable.
* **`forEach` Method**: A more modern and concise way of iterating over arrays using a callback function.

**Pros and Cons**

Here's a brief analysis of each approach:

1. **Traditional For Loop (`for`)**:
	* Pros: Easy to read and understand, widely supported by most browsers.
	* Cons: Can be slower due to the overhead of manual indexing.
2. **Incrementing Pre-Increment `For` Loop (`pre increment for`)**:
	* Pros: May offer better performance in specific use cases, but is not a standard JavaScript feature.
	* Cons: Less readable and less widely supported by browsers.
3. **`forEach` Method**:
	* Pros: More modern, concise, and easy to read, with good support across most browsers.
	* Cons: Might be slower due to the overhead of method call and callback execution.

**Other Considerations**

When testing performance-critical code like this, it's essential to consider factors beyond just loop syntax. These may include:

* Array size and initialization
* Data type and allocation
* Browser-specific optimizations or limitations
* Other external factors that might influence performance (e.g., network latency, disk I/O)

**Alternative Approaches**

If you wanted to test alternative approaches, you could consider adding additional benchmark cases, such as:

* **While Loop**: Another traditional loop syntax for iterating over arrays.
* **Array.prototype.reduce()**: A more functional approach to reducing array elements to a single value.
* **Set or Map Iteration**: Testing the performance of these data structures when iterated using standard methods.

Keep in mind that each additional test case would require modifying the benchmark script and potentially affecting the overall execution time.

Related benchmarks:

for tests (version: 0)

Comparing performance of: forEach vs for vs pre increment for

Created: 2 years ago by: Guest

Jump to the latest result

forEach

for

pre increment for

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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