Benchmark: Shallow Copy Array

Script Preparation code:

var newArr = ['1', '2', '3', '4'];

Tests:

Slice
const arrCopy = newArr.slice()
Spread
const arrCopy = [...newArr]
Array.from
const arrCopy = Array.from(newArr)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Slice
Spread
Array.from

Fastest: N/A

Slowest: N/A

Latest run results:

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

LLMs can make mistakes. Check important info.

**Benchmark Explanation**

The provided benchmark measures the performance of creating shallow copies of an array in JavaScript using three different methods: `slice()`, spread operator (`...`), and `Array.from()`.

**Methods Compared**

1. **Slice()**: This method creates a new array by slicing the original array from index 0 to the end.
2. **Spread Operator (`...`)**: This method creates a new array by spreading the elements of the original array into a new array.
3. **Array.from()**: This method creates a new array from an iterable (in this case, the original array).

**Pros and Cons**

1. **Slice()**:
	* Pros: Simple and efficient, as it only requires a single function call.
	* Cons: May not be suitable for large arrays due to memory allocation overhead.
2. **Spread Operator (`...`)**:
	* Pros: Can create shallow copies of larger arrays without the need for explicit loops or array methods.
	* Cons: Requires JavaScript version 13+ (or later) and may have performance implications due to the creation of a new array object.
3. **Array.from()**:
	* Pros: Can create shallow copies of larger arrays with a single function call, similar to the spread operator.
	* Cons: May not be as efficient as `slice()` for very large arrays.

**Library Usage**

None of the provided methods use any external libraries.

**Special JavaScript Features/Syntax**

The test cases use the following special JavaScript features/syntax:

* **Spread Operator (`...`)**: This feature is only available in JavaScript version 13+ (or later).
* None other syntax are used.

**Other Alternatives**

If you need to create shallow copies of arrays in JavaScript, there are two alternative methods:

1. **Loops**: You can use a simple loop to create a new array and copy the elements from the original array.
2. **Array.prototype.map()**: This method returns a new array with the same number of elements as the original array, where each element is copied from the corresponding element in the original array.

Example:
```javascript
const arrCopy = [];
for (let i = 0; i < newArr.length; i++) {
    arrCopy.push(newArr[i]);
}
```
or
```javascript
const arrCopy = newArr.map((element) => {
    // You can add additional logic here if needed
    return element;
});
```

Keep in mind that these alternatives may not be as efficient or concise as the methods used in the benchmark, but they can be useful in certain situations.

Related benchmarks:

Shallow Copy Array (version: 0)

Comparing performance of: Slice vs Spread vs Array.from

Created: 3 years ago by: Guest

Jump to the latest result

Slice

Spread

Array.from

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):