Benchmark: Array.from->map vs Array.prototype.map.call

Script Preparation code:

var a = "abcdefghijklmnopqrstuvwxyz";

Tests:

Array.from->map
Array.from(a).map(()=>a.toUpperCase());
Array.prototype.map.call
Array.prototype.map.call(a,()=>a.toUpperCase());

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.from->map
Array.prototype.map.call

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.6.1 Safari/605.1.15

Browser/OS: Safari 17 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Array.from->map	806951.2 Ops/sec
Array.prototype.map.call	550522.3 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the explanation.

**Benchmark Definition and Options Comparison**

The provided benchmark compares two approaches to iterate over an array:

1. `Array.from(a).map(() => a.toUpperCase())`
2. `Array.prototype.map.call(a, () => a.toUpperCase())`

These two approaches aim to achieve the same result: converting the characters of the string "abcdefghijklmnopqrstuvwxyz" into uppercase using the `toUpperCase()` method.

**Approach 1: Using `Array.from` and `.map()`**

This approach uses the `Array.from()` method to create a new array from the input string, followed by the `.map()` method to apply the transformation function (`a.toUpperCase()`) to each element in the array. The resulting array is then returned.

Pros:

* Clear and concise syntax
* No need to specify the length of the array

Cons:

* Creates a new array, which may incur additional memory overhead
* Requires two function calls, which can lead to more overhead than a single call with `Array.prototype.map.call()`

**Approach 2: Using `Array.prototype.map.call()`**

This approach uses the `map()` method on the original string (wrapped in an array using `Array.prototype.call()`), passing a callback function (`a.toUpperCase()`) to apply the transformation. The resulting transformed array is returned.

Pros:

* Does not create a new array, which can reduce memory overhead
* Only requires one function call

Cons:

* Requires careful consideration of the input type and length to ensure correct behavior
* May lead to slower performance due to the need for an extra function call

**Library and Special Features**

None of the approaches rely on specific libraries or JavaScript features other than built-in methods (`Array.from()`, `map()`, `.toUpperCase()`). No special features are used in these benchmarks.

**Alternative Approaches**

Other possible approaches could include:

1. Using `String.prototype.toUpperCase()` directly on the input string, without creating an array: `a.split('').map(c => c.toUpperCase()).join('')`
2. Using a library like Lodash or Ramda to perform the mapping operation
3. Using a custom loop with `for`-style iteration instead of `.map()`

However, these alternatives are not part of the original benchmark and would likely introduce additional overhead or complexity.

**Benchmark Preparation Code**

The preparation code creates an array from the string "abcdefghijklmnopqrstuvwxyz" using `Array.from()` and assigns it to the variable `a`. This setup ensures that both test cases have access to a valid input array.

Related benchmarks:

Array.from->map vs Array.prototype.map.call (version: 0)

Comparing performance of: Array.from->map vs Array.prototype.map.call

Created: 3 years ago by: Guest

Jump to the latest result

Array.from->map

Array.prototype.map.call

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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