Benchmark: Array loop vs foreach vs map 100k

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 provided benchmark and explain what's being tested, compared, and discussed.

**Benchmark Overview**

The benchmark compares three different ways to iterate over an array of numbers:

1. **For Loop**: A traditional loop that uses a `for` statement to iterate over the array indices.
2. **Array.prototype.forEach()**: A method that iterates over the elements of an array using a callback function.
3. **Array.prototype.map()**: A method that creates a new array by applying a transformation function to each element of the original array.

**Options Compared**

The benchmark compares these three options for two reasons:

1. **Performance**: Which iteration method is faster? The test measures the number of executions per second (ExecutionsPerSecond) for each option.
2. **Code Complexity**: Which iteration method results in simpler or more concise code?

**Pros and Cons of Each Approach**

1. **For Loop**:
	* Pros: Easy to understand, flexible, and can be used with other data structures like objects or sets.
	* Cons: Can be verbose, especially when dealing with large arrays or complex logic.
2. **Array.prototype.forEach()**:
	* Pros: Convenient, easy to read, and provides a clear separation of concerns between iteration and transformation logic.
	* Cons: May incur a small performance overhead due to the use of an intermediate callback function.
3. **Array.prototype.map()**:
	* Pros: Provides a concise way to transform data while iterating over it, making it suitable for tasks like array processing.
	* Cons: May be less performant than a traditional loop or `forEach()` due to the creation of an intermediate array.

**Library and Special JS Features**

The benchmark uses the following JavaScript features:

1. **Array.prototype.forEach()**: A built-in method for iterating over arrays, introduced in ECMAScript 5 (ES5).
2. **Array.prototype.map()**: Also a built-in method, introduced in ES5.
3. **Arrow functions** (`=>`): Introduced in ES6 (ECMAScript 2015) as a concise way to define small, single-expression functions.

**Other Alternatives**

For larger-scale tasks or more complex data processing, other alternatives might be considered:

1. **Reduce()**: A method for reducing an array to a single value, suitable for aggregation operations.
2. **Iterators and Generators**: For creating custom iteration mechanisms or handling large datasets efficiently.
3. **Third-party libraries** (e.g., Lodash): For more advanced data processing tasks or when working with complex data structures.

Keep in mind that these alternatives may not be relevant to this specific benchmark, which focuses on simple array iteration and transformation.

Related benchmarks:

Array loop vs foreach vs map 100k (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):