Benchmark: Array loop vs foreach vs map (large set)

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

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

LLMs can make mistakes. Check important info.

Let's break down the JavaScript microbenchmark and explain what is being tested.

The benchmark is designed to compare the performance of three different approaches:

1. **`forEach` loop**: This approach uses the `forEach` method, which calls a provided function for each element in an array.
2. **Traditional `for` loop**: This approach uses a traditional `for` loop with an index variable to iterate over the elements in the array.
3. **`map` method**: This approach uses the `map` method, which returns a new array containing the results of applying a provided function to each element in the original array.

**Pros and Cons:**

* **`forEach` loop**: Pros:
	+ Easier to read and write code
	+ Less chance of off-by-one errors (since it automatically handles index values)
	+ Can be more efficient for certain use cases (e.g., when the iteration order matters)
*   Cons:
    + Can be slower than traditional loops due to function call overhead
    + May have performance issues if the array is very large, since it has to create a new scope on each iteration
*   Traditional `for` loop: Pros:
	+ Often faster than `forEach` loop for large arrays (since it avoids function call overhead)
	+ Can provide more control over indexing and iteration order
    Cons:
    + More error-prone due to manual index management
    + Less readable code, especially for complex iterations
*   `map` method: Pros:
    + Returns a new array, which can simplify further processing
    + Often faster than traditional loops (since it avoids unnecessary function calls)
	Cons:
    + Can be slower than traditional loops when the iteration order doesn't matter
    + May require more memory allocation for the returned array

**Library and Purpose:**

The `someFn` function is a simple example function that takes an integer value as input, multiplies it by 3, and then by 8. It serves no special purpose other than to illustrate the different iteration methods.

**Special JavaScript Features or Syntax:**

This benchmark does not use any special JavaScript features or syntax beyond what is commonly used in modern web development (e.g., `forEach`, `for` loops, arrow functions, etc.). There are no specific ES6+ features like async/await, promises, or generator functions used here.

**Alternatives:**

Other alternatives for benchmarking array iteration performance might include:

* Using a different JavaScript engine or version
* Increasing or decreasing the size of the input array
* Testing with different data types (e.g., strings, numbers, objects)
* Incorporating additional operations within each iteration (e.g., calculations, memory allocations)
* Exploring parallelization or concurrent execution for improved performance

Related benchmarks:

Array loop vs foreach vs map (large set) (version: 0)

Comparing performance of: foreach vs for vs map

Created: 6 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):