Benchmark: djkencioemzio foreach vs for loop

Tests:

foreach
var array = new Array(1000000).fill(0); array.forEach((_,i,a) => a[i]=i);
for loop
var array2 = new Array(1000000).fill(0); for (let i = 0; i < array2.length; i++) array2[i] = i;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
foreach
for loop

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

**What is being tested?**

The provided JSON represents two individual test cases for measuring the performance of JavaScript loops. Specifically, they compare the execution time and efficiency of two types of loops: `forEach` and `for` loop.

**Options compared:**

Two options are compared:

1. **`forEach`**: This is a method on arrays that executes a provided callback function once for each element in the array.
2. **`for` loop**: This is a traditional loop construct that uses an index variable to iterate over an array.

**Pros and cons of each approach:**

**`forEach`**:

Pros:

* Simplifies code by eliminating the need to manually keep track of indices.
* Easier to read and write, especially for simple transformations or filtering operations.

Cons:

* Can be slower than `for` loops because it involves additional overhead from the array's internal indexing mechanism.
* May incur more memory allocations due to the creation of temporary objects (e.g., `Array.prototype.forEach()` creates a new object with the callback function).

**`for` loop**:

Pros:

* Typically faster and more efficient, especially for large datasets, since it avoids the overhead of array indexing.
* More control over iteration and index management.

Cons:

* Requires manual handling of indices, which can increase code complexity and error-prone.

**Other considerations:**

* Both approaches have their use cases. `forEach` is suitable for simple transformations or filtering operations, while `for` loops are better suited for complex iterations or when precise control over the iteration process is required.
* The choice between `forEach` and `for` loop ultimately depends on the specific requirements of the project and personal preference.

**Library:**

None mentioned in the provided JSON. However, if a library like Lodash's `forEach` function were used, it would likely provide additional features or optimizations that could impact performance.

**Special JS feature/syntax:**

None mentioned in the provided JSON. However, it's worth noting that modern JavaScript versions (e.g., ECMAScript 2022+) introduced features like `for...of`, which can simplify iteration over arrays and objects, potentially offering better performance than traditional `for` loops or `forEach`.

**Alternatives:**

1. **Other loop constructs:** Besides `forEach` and `for` loops, other loop constructs like `while` loops or `do...while` loops could be used for comparison.
2. **Native array methods:** Other native array methods, such as `map()`, `filter()`, or `reduce()`, could also be compared for performance in specific scenarios.
3. **Loop unrolling and optimization techniques:** Optimizing loop performance using techniques like loop unrolling, caching, or parallelization could provide additional insights into the best approach.

In conclusion, the provided benchmark compares two common JavaScript loop constructs: `forEach` and `for` loops. The choice between these approaches depends on the specific use case, personal preference, and performance requirements.

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/108.0.0.0 Safari/537.36

Browser/OS: Chrome 108 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
foreach	48.1 Ops/sec
for loop	170.7 Ops/sec

Related benchmarks:

djkencioemzio foreach vs for loop (version: 0)

Comparing performance of: foreach vs for loop

Created: one year ago by: Guest

Jump to the latest result

foreach

for loop

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):