Benchmark: Array.from vs array.forEach

Tests:

Array.from
var fooSet = new Set(); for(var i=0;i<100;i++) { fooSet.add(i); } var other = Array.from(fooSet);
forEach
var fooSet = new Set(); for(var i=0;i<100;i++) { fooSet.add(i); } const other = []; fooSet.forEach((foo) => { other.push(foo); });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.from
forEach

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.

Let's dive into the explanation of the provided benchmark.

**What is being tested?**

The benchmark measures the performance difference between two approaches to convert a Set object to an Array:

1. `Array.from(fooSet)`
2. `fooSet.forEach((foo) => { other.push(foo); })`

In this test case, we have a Set object (`fooSet`) containing integers from 0 to 99, and we're comparing the execution time of two methods to create an equivalent array: using `Array.from()` or using the `forEach` method with a callback function.

**Options compared**

The two options being tested are:

1. **`Array.from(fooSet)`**: This method creates a new Array from the Set object, including all elements.
2. **`fooSet.forEach((foo) => { other.push(foo); })`**: This approach iterates over each element in the Set object and pushes it to an existing array (`other`).

**Pros and Cons of each approach**

1. `Array.from(fooSet)`:
	* Pros: concise, efficient, and modern.
	* Cons: may not be as intuitive for those unfamiliar with this method, and performance might vary depending on browser support.
2. `fooSet.forEach((foo) => { other.push(foo); })`:
	* Pros: widely supported in older browsers and more familiar to developers, allowing for easier maintenance and debugging.
	* Cons: less efficient due to the overhead of iterating over each element individually.

**Library used**

In both test cases, we're using a Set object (`fooSet`) as input. A Set is a collection of unique values, which makes it suitable for this benchmark.

**Special JS feature or syntax**

There are no special features or syntaxes being tested in these examples.

Now, let's talk about other alternatives:

1. **Using `Array.prototype.slice()`**: Another approach to create an array from a set would be to use the `slice()` method, but it requires more code and is less efficient than both options.
2. **Using libraries like Lodash or Ramda**: These libraries provide utility functions for working with arrays and sets, but they may introduce additional dependencies and overhead.

**Additional considerations**

When writing benchmarks, it's essential to consider the following:

1. **Test scope**: Is the benchmark testing a specific aspect of performance (e.g., speed) or a broader set of characteristics?
2. **Test duration**: How long does the test run? A short duration may not accurately represent real-world performance.
3. **Browser support**: Does the benchmark account for differences in browser versions and features?

By understanding these factors, you can ensure that your benchmarks are accurate, reliable, and meaningful.

Related benchmarks:

Array.from vs array.forEach (version: 0)

Comparing performance of: Array.from vs forEach

Created: 3 years ago by: Guest

Jump to the latest result

Array.from

forEach

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):