Benchmark: fill vs from Array vs from object

Tests:

fill
Array(1e7).fill().map((_, i) => i+1)
from
Array.from(Array(1e7), (_, i) => i+1)
from object
Array.from({length: 1e7}, (_, i) => i+1)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
fill
from
from object

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):

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Let's break down the benchmark and explain what's being tested, the options compared, their pros and cons, and other considerations.

**Benchmark Definition**

The benchmark is comparing three approaches to create an array of numbers:

1. `fill()`: Using the `fill()` method to create a new array filled with values.
2. `Array.from()`: Using the `Array.from()` method to create a new array from an existing iterable (in this case, another array).
3. `from object` (using the spread operator): Using the spread operator (`...`) to create a new array from an object.

**Options Compared**

The three options are being compared in terms of their performance, which is measured by the number of executions per second.

* **Pros and Cons:**
	+ `fill()`: Pros - simple and concise syntax. Cons - can be slower due to the creation of a new array.
	+ `Array.from()`: Pros - more flexible than `fill()` and allows for custom iterables. Cons - may incur additional overhead due to the use of an intermediate iterable.
	+ `from object` (using spread operator): Pros - concise syntax and can be faster than `fill()` since it avoids creating a new array. Cons - may not work as expected if the object is large or has complex structure.
* **Other Considerations:**
	+ The benchmark does not account for memory allocation or garbage collection, which could impact performance in certain scenarios.

**Libraries and Special JS Features**

None of the benchmarks use external libraries, but they do utilize some advanced JavaScript features:

* `Array.from()`: Uses the `Array.from()` method to create a new array from an existing iterable.
* `from object` (using spread operator): Uses the spread operator (`...`) to extract values from an object.

**Benchmark Preparation Code**

The benchmark preparation code is empty, which means that the script only defines the three test cases and does not perform any additional setup or validation.

**Individual Test Cases**

Each test case defines a single scenario:

1. `fill()`: Creates a new array using the `fill()` method to generate an array of numbers.
2. `Array.from()`: Creates a new array from an existing array using the `Array.from()` method to generate an array of numbers.
3. `from object` (using spread operator): Creates a new array by extracting values from an object using the spread operator (`...`) and generating an array of numbers.

**Benchmark Results**

The latest benchmark results show the performance of each test case across different browsers, devices, and platforms:

* `fill()`: Performed best in all cases, with an average execution rate of 1.68 executions per second.
* `Array.from()`: Performed second-best, with an average execution rate of 1.12 executions per second.
* `from object` (using spread operator): Performed worst, with an average execution rate of 1.03 executions per second.

**Alternatives**

Some alternative approaches to create arrays could be:

* Using a loop: `for (let i = 0; i < 1e7; i++) { ... }`
* Using the `Array` constructor with the `new` keyword: `var arr = new Array(1e7).fill().map((_, i) => i + 1);`

However, these approaches are generally slower and less concise than the methods used in the benchmark.

Related benchmarks:

fill vs from Array vs from object (version: 0)

Comparing performance of: fill vs from vs from object

Created: 4 years ago by: Guest

Jump to the latest result

fill

from

from object

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):