Benchmark: Array.from vs Spread2

Tests:

Array.from
function range(start, end) { const length = end - start + 1; return Array.from({ length }, (_, i) => start + i); } range(0,1000);
Spread
function range(start, end) { const size = end - start + 1; return [...Array(size).keys()].map((i) => i + start); } range(0, 1000);

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:

No previous 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 break down the provided benchmark and explain what's being tested.

**Benchmark Overview**

The benchmark compares two ways to create an array of sequential numbers: `Array.from` and the spread operator (`...`). The script preparation code is empty, which means that the benchmark only focuses on the differences between these two syntaxes.

**Options Compared**

There are two options compared:

1. **Array.from**: This method creates a new array from an iterable (in this case, an object with a length property) by repeatedly calling `push` and passing the element to be pushed.
2. **Spread Operator (`...`)**: This operator is used to expand a list of arguments into individual elements inside parentheses.

**Pros and Cons**

* **Array.from**: Pros:
	+ More explicit and readable, as it explicitly states that an array is being created from an iterable.
	+ May be faster for large arrays due to the optimized `push` method in V8 (the JavaScript engine used by most browsers).
Cons:
	+ May have a slight performance overhead compared to the spread operator.
* **Spread Operator (`...`)**: Pros:
	+ More concise and readable, as it allows you to create an array from a list of elements without explicitly creating an intermediate iterable.
	+ May be faster for large arrays due to the optimized `Array.prototype.push` method in V8.
Cons:
	+ Less explicit and may require additional effort to understand its intent.

**Library and Purpose**

There is no external library used in this benchmark. The only libraries that come into play are:

* **V8**: This is the JavaScript engine used by most browsers, including Safari 15, which runs the benchmark.
* **ECMAScript**: This is a standard for describing the syntax and semantics of JavaScript.

**Special JS Feature or Syntax**

There is no special feature or syntax mentioned in this benchmark. The code only uses standard JavaScript features like `Array.from`, spread operator (`...`), and `push`.

**Other Considerations**

When writing benchmarks, it's essential to consider factors such as:

* **Hardware and Software**: The specific hardware (e.g., CPU, GPU) and software configuration used during the benchmarking process.
* **Language Features**: Any language-specific features or syntaxes that might affect performance or readability.
* **Code Optimization**: Techniques like inlining, loop unrolling, or caching can impact performance.

**Alternatives**

If you want to create an array of sequential numbers without using `Array.from` or the spread operator, you could consider other methods like:

* Using a `for` loop with an index variable: `let result = []; for (let i = 0; i < 1000; i++) { result.push(i); }`
* Using the `Array.prototype.fill` method: `let result = new Array(1000).fill(0);`

Keep in mind that these alternatives might have a different performance profile or readability compared to the original options.

Related benchmarks:

Array.from vs Spread2 (version: 0)

Comparing performance of: Array.from vs Spread

Created: 4 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):