Benchmark: Array.prototype.map() VS Spread

Script Preparation code:

permutations = new Array(10000).map(() => ('lorem ipsum live long and prosper'));

Tests:

Spread
const updated = [...permutations]; return updated;
Array.map
const updated = permutations.map(item => item); return updated;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Spread
Array.map

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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**Benchmark Definition and Script Preparation Code**

The benchmark is designed to compare two approaches for creating a shallow copy of an array: using the spread operator (`...`) or the `Array.prototype.map()` method. The script preparation code generates an array of 10,000 strings, which will be used as input for both test cases.

**Test Cases**

There are two individual test cases:

1. **Spread**: This test case uses the spread operator to create a shallow copy of the `permutations` array and assigns it to a new variable called `updated`. The resulting array is then returned.
2. **Array.map**: This test case uses the `Array.prototype.map()` method to create a shallow copy of the `permutations` array, applies an identity function (i.e., returns each element unchanged) to each element, and assigns the result to a new variable called `updated`. The resulting array is then returned.

**Library: None**

Neither test case uses any external libraries. The spread operator is a built-in JavaScript feature, while the `Array.prototype.map()` method is also part of the standard library.

**Special JS Features/Syntax**

There are no special JavaScript features or syntax used in these test cases. They rely solely on standard language constructs and built-in methods.

**Options Compared**

The two test cases compare two different approaches to creating a shallow copy of an array:

1. **Spread Operator**: Creates a new array by copying the elements from the original array using the spread operator (`...`).
2. **Array.prototype.map()**: Uses the `map()` method to create a new array with the same number of elements as the original array, but with each element transformed or copied (in this case, using an identity function).

**Pros and Cons**

Here are some pros and cons for each approach:

* **Spread Operator**:
	+ Pros: Fast, efficient, and concise.
	+ Cons: May not work as expected if the spread operator is used with other methods (e.g., `Array.prototype.slice()`).
* **Array.prototype.map()**:
	+ Pros: Allows for more flexibility in transforming or copying array elements.
	+ Cons: Can be slower than the spread operator, especially for large arrays.

**Other Considerations**

In general, when deciding between these two approaches, consider the following:

* If you need to create a shallow copy of an array and don't care about modifying the original array, use the spread operator.
* If you need to perform additional operations on each element in the array, such as transforming or copying values, use the `Array.prototype.map()` method.

**Alternative Approaches**

Other approaches for creating a shallow copy of an array include:

1. **Array.prototype.slice()**: Creates a new array by copying elements from the original array using `slice()`.
2. **Array.from()**: Creates a new array from an iterable source (e.g., an array or string) using `from()`.
3. **Object.assign()**: Creates a new object by copying properties from an existing object using `assign()`.

Keep in mind that each approach has its own trade-offs and considerations, so choose the one that best fits your specific use case.

Related benchmarks:

Array.prototype.map() VS Spread (version: 0)

Comparing performance of: Spread vs Array.map

Created: 4 years ago by: Guest

Jump to the latest result

Spread

Array.map

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):