Benchmark: copy array with foreach for and map

Script Preparation code:

   var arr = [];
    for (var i = 0; i < 1000; i++) {
      arr[i] = i;
    }

Tests:

foreach
var arr2 = []; arr.forEach(item => arr2.push(item))
for
var arr2 = []; for (var i = 0, len = arr.length; i < len; i++) { arr2.push(arr[i]); }
map
var arr2 = arr.map(item => 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:

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

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I'll break down the provided benchmark and explain what's being tested.

**Benchmark Overview**

The benchmark measures the performance of three different approaches to copy an array in JavaScript:

1. Using `forEach` with a callback function
2. Using a traditional `for` loop
3. Using the `map()` method

**Library: Lodash**

In the provided benchmark, Lodash is used as a library for its `forEach()` and `map()` functions. Lodash is a popular JavaScript utility library that provides a wide range of useful functions, including those for array manipulation.

**Special JS Feature/Syntax**

There are no special JavaScript features or syntax mentioned in this benchmark. The focus is on the three different approaches to copying an array.

**Options Compared**

The benchmark compares the performance of three different approaches:

1. `forEach` with a callback function (Lodash)
2. Traditional `for` loop
3. `map()` method (Lodash)

**Pros and Cons of Each Approach**

Here's a brief summary of each approach:

* **ForEach with Callback Function (Lodash)**:
	+ Pros: Easy to read and maintain, concise code.
	+ Cons: May have performance overhead due to the callback function invocation.
* **Traditional `for` Loop**:
	+ Pros: Simple and straightforward, no overhead from a callback function.
	+ Cons: Can be less readable and more verbose than other approaches.
* **Map() Method (Lodash)**:
	+ Pros: Concise and expressive, creates a new array without modifying the original.
	+ Cons: May have performance overhead due to the creation of a new array.

**Benchmark Results**

The benchmark results show that:

1. The `map()` method with Lodash has the highest execution rate (ExecutionsPerSecond), indicating it's likely the fastest approach.
2. The traditional `for` loop has a significantly lower execution rate, suggesting it may be slower than other approaches due to its simplicity and lack of optimization.
3. The `forEach` with a callback function using Lodash falls in between, with an intermediate execution rate.

**Other Alternatives**

There are other ways to copy an array in JavaScript, such as:

* Using the spread operator (`arr.slice()` or `arr Spred()`)
* Using the `Array.prototype.slice()` method
* Using a custom implementation with a loop

However, these alternatives may not be included in this specific benchmark.

In summary, the benchmark highlights the performance differences between three approaches to copying an array in JavaScript. The results suggest that the `map()` method with Lodash is likely the fastest approach, followed by a traditional `for` loop and then `forEach` with a callback function using Lodash.

Related benchmarks:

copy array with foreach for and map (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):