Benchmark: Array.from vs Spread. Map

Tests:

Array.from
var fooMap = new Map(); for(var i=0;i<100;i++) { fooMap.set(i, { id: i }); } var other = Array.from(fooMap, ([name, value]) => value);
Spread
var fooMap = new Map(); for(var i=0;i<100;i++) { fooMap.set(i, { id: i }); } var other = [...fooMap].map(([name, value]) => value);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.from
Spread

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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Let's break down the provided benchmark and explain what's being tested, compared, and analyzed.

**Benchmark Overview**

The test compares two approaches to iterate over a Map object in JavaScript:

1. `Array.from(fooMap, ([name, value]) => value)`
2. `var other = [...fooMap].map(([name, value]) => value);`

Both approaches aim to transform the Map's values into an array of objects.

**Approach 1: `Array.from()`**

`Array.from()` is a method that creates a new Array instance from an iterable or an array-like object. In this case, it's used with the `Map` object as its first argument, and a callback function is provided to transform each value into an object.

**Pros of using `Array.from()`:**

* It's a modern JavaScript feature, which might imply better performance.
* It's often considered more concise and expressive than other approaches.

**Cons of using `Array.from():**

* Performance might be slower due to the overhead of creating an array from an iterable.
* Some older browsers or environments might not support it.

**Approach 2: Destructuring with Spread (`[...fooMap].map()`)**

This approach uses the spread operator (`[...]`) to convert the Map into an array, followed by the `map()` method to transform each value. The destructuring syntax `[name, value]` is used to extract the key-value pairs from the Map's values.

**Pros of using this approach:**

* Performance might be comparable or better than `Array.from()`, depending on the JavaScript engine.
* This approach is more widely supported across browsers and environments.

**Cons of using this approach:**

* It can be considered less concise and more verbose than `Array.from()`.
* The spread operator requires JavaScript version 7 or later to work.

**Library/Learning Points**

In both test cases, the Map object from the built-in JavaScript API is used. No external libraries are imported, but if you're interested in exploring other map-like data structures, consider looking into:

* `Map` objects (built-in JavaScript API)
* Third-party libraries like Lodash or Ramda for functional programming utilities.

**Special JavaScript Features/ Syntax**

This benchmark doesn't explicitly use any special JavaScript features or syntax, such as ES6 modules, async/await, or modern promises. However, if you're interested in exploring these topics further:

* Consider looking into the latest ECMAScript standards and browser support.
* Explore resources like MDN Web Docs or freeCodeCamp for learning more about modern JavaScript.

**Other Alternatives**

If you want to explore other approaches to iterate over a Map object, consider using:

* `for...of` loops with a custom iterator function.
* Using the `entries()` method on the Map object (available in ECMAScript 2015 and later).
* Implementing a recursive function or a generator function to process the Map's values.

Keep in mind that each alternative might have its own trade-offs, performance characteristics, and compatibility across browsers and environments.

Related benchmarks:

Array.from vs Spread. Map (version: 0)

Comparing performance of: Array.from vs Spread

Created: 3 years ago by: Guest

Jump to the latest result

Array.from

Spread

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):