Benchmark: Array loop vs foreach vs map sdadasdsa 2 - no func - store arr

Script Preparation code:

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

Tests:

foreach
arr.forEach(function (item){ item = item * 3 * 8 })
for
for (let i = 0; i < arr.lenght; i++) { arr[i] = arr[i] * 3 * 8 }
map
arr.map(item => item = item * 3 * 8)

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:

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

LLMs can make mistakes. Check important info.

I'd be happy to help explain the provided benchmark!

**What is being tested?**

The provided benchmark tests three different approaches for iterating over an array in JavaScript:

1. **Array loop**: A traditional `for` loop that iterates over the array using an index variable.
2. **`forEach()`**: The `forEach()` method, which calls a function for each element in the array.
3. **`map()`**: The `map()` method, which creates a new array with the results of applying a given function to each element.

**Options compared**

The benchmark compares the performance of these three approaches on an array of 10,000 elements, where each element is initialized with its index value multiplied by 3 and then multiplied by 8.

**Pros and Cons of each approach**

1. **Array loop**:
	* Pros: Can be controlled exactly (e.g., specifying which elements to process), can use any iteration mechanism, and may have better cache locality.
	* Cons: Can be slower due to the overhead of manual index management, and may not take advantage of modern CPU features like SIMD instructions.
2. **`forEach()`**:
	* Pros: Easy to read and maintain, concise syntax, and can avoid manual indexing issues.
	* Cons: May have performance overhead due to function calls and object lookup, and may not optimize well for modern CPUs.
3. **`map()`**:
	* Pros: Creates a new array with transformed elements, which can be useful in functional programming, and can take advantage of SIMD instructions.
	* Cons: Returns a new array, which can incur memory allocation overhead, and may have slower performance compared to `forEach()` due to the creation of an intermediate array.

**Library usage**

None of the provided benchmarks use any libraries or external dependencies. They only utilize built-in JavaScript features.

**Special JS feature/syntax**

The `map()` method uses a shorthand syntax, specifically the arrow function (`item => item = item * 3 * 8`), which is a concise way to define a small anonymous function. This syntax was introduced in ECMAScript 2015 (ES6) and has since become widely adopted.

**Other alternatives**

For comparing performance in JavaScript, other approaches might include:

1. **`reduce()`**: Similar to `map()`, but returns a single value instead of an array.
2. **`filter()`**: Removes elements from the array based on a given condition.
3. **NativeArray operations**: Some modern browsers support native array operations like `at()`, `fill()`, and `set()`, which can be faster than using JavaScript methods.

Keep in mind that the performance of these alternatives may vary depending on the specific use case, browser, and hardware.

Related benchmarks:

Array loop vs foreach vs map sdadasdsa 2 - no func - store arr (version: 0)

Comparing performance of: foreach vs for vs map

Created: 4 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):