Benchmark: Array loop vs foreach vs map asb

Script Preparation code:

   var arr = [];
    for (var i = 0; i < 100000; i++) {
      arr[i] = i;
    }
  
    function someFn(i) {
      return i * 3 * 8;
    }

Tests:

foreach
arr.forEach(function (item){ someFn(item); })
for
for (var i = 0, len = arr.length; i < len; i++) { someFn(arr[i]); }
map
arr.map(item => someFn(item))

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
foreach
for
map

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks!

The provided JSON represents a benchmark test case for measuring the performance of three different approaches: `for`, `foreach`, and `map` loops when working with arrays in JavaScript.

**What is being tested?**

In this benchmark, we have an array of 100,000 elements initialized with incremental values from 0 to 99,999. A function `someFn(i)` is defined, which takes a single argument `i` and returns the result of `i * 3 * 8`. This function is intended to be executed in each iteration of the loop.

**Options being compared:**

1. **For Loop**: A traditional `for` loop is used to iterate over the array elements.
2. **Foreach Loop**: The `forEach()` method is used, which calls a callback function for each element in the array.
3. **Map Function**: The `map()` function is used, which returns a new array with the results of applying the provided function to each element.

**Pros and Cons:**

1. **For Loop**:
	* Pros: More control over iteration, can be optimized with caching or other techniques.
	* Cons: Can be slower due to the overhead of managing loop variables and indexing.
2. **Foreach Loop**:
	* Pros: Concise and readable syntax, eliminates the need for manual indexing.
	* Cons: May have additional overhead due to function calls and context switching.
3. **Map Function**:
	* Pros: Efficient and concise, returns a new array with transformed elements.
	* Cons: Creates an additional array object, which can be memory-intensive.

**Library/Language Features:**

None of the benchmarked features explicitly use any special JavaScript libraries or syntax beyond standard ECMAScript features. However, it's worth noting that some modern browsers may enable experimental features like `let` and `const` for variable declarations, but this is not relevant to the specific benchmark being tested.

**Other Considerations:**

* The benchmark uses a relatively small array size (100,000 elements). Larger arrays would likely lead to more significant differences in performance.
* The `someFn()` function is simple and does not rely on any special optimizations or caching. More complex functions might require additional consideration when choosing an iteration approach.
* This benchmark focuses on the relative performance of different iteration methods within a single function call. Other microbenchmarks might investigate specific use cases, such as iterative algorithms versus recursive ones.

**Alternatives:**

Some other alternatives for measuring array processing performance in JavaScript include:

1. **Native Array Functions**: Using native functions like `reduce()`, `filter()`, or `every()` can provide a more accurate representation of the language's capabilities.
2. **Web Workers**: Running the benchmark using Web Workers, which allow concurrent execution of tasks, might help mitigate limitations due to browser-specific optimizations.
3. **Alternative Iteration Methods**: Exploring other iteration methods like `while` loops, array destructuring, or bitwise operations could reveal additional performance characteristics.

Keep in mind that this is not an exhaustive list, and there are many variations on these benchmarks.

Related benchmarks:

Array loop vs foreach vs map asb (version: 0)

Comparing performance of: foreach vs for vs map

Created: 5 years ago by: Guest

Jump to the latest result

foreach

for

map

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):