Benchmark: Array.prototype.concat vs spread operator test 34234

Tests:

Array.prototype.concat
var params = [ "hello", true, 7 ]; var other = [ 1, 2 ].concat(params);
spread operator
var params = [ "hello", true, 7 ] var other = [ 1, 2, ...params ]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.prototype.concat
spread operator

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

Autogenerated LLM Summary (model llama3.1:latest, generated one year ago):

LLMs can make mistakes. Check important info.

Let's dive into the details of this benchmark.

**What is being tested?**

This benchmark compares two ways to concatenate (merge) arrays in JavaScript:

1. Using the `concat()` method (`Array.prototype.concat`).
2. Using the spread operator (`...`) introduced in ECMAScript 6 (ES6).

**Test cases:**

There are two test cases, each representing one of the methods being compared.

**Test case 1: Array.prototype.concat**

This test case uses the traditional `concat()` method to merge an array `[1, 2]` with another array containing string and boolean values (`params`). The code is as follows:
```javascript
var params = [ "hello", true, 7 ];
var other = [ 1, 2 ].concat(params);
```
Here, `concat()` is called on the initial array `[1, 2]` with the `params` array as its argument. This creates a new array containing all elements from both arrays.

**Test case 2: Spread operator**

This test case uses the spread operator (`...`) to merge an array `[1, 2]` with another array containing string and boolean values (`params`). The code is as follows:
```javascript
var params = [ "hello", true, 7 ];
var other = [ 1, 2, ...params ];
```
Here, the spread operator is used to merge the `params` array into a new array with `[1, 2]`.

**What are the options compared?**

The two test cases compare the performance of using:

1. `Array.prototype.concat`: A traditional method that creates a new array by concatenating two existing arrays.
2. Spread operator (`...`): An ES6 feature that allows merging an array with other iterables (like another array).

**Pros and cons:**

* **Array.prototype.concat**: Pros:
	+ More widely supported in older browsers (pre-ES6).
	+ Easy to understand for developers familiar with traditional JavaScript.
* Cons:
	+ Creates a new array, which can be memory-intensive if arrays are large.
	+ Less concise than the spread operator syntax.

* **Spread operator (`...`)**: Pros:
	+ More concise and expressive syntax.
	+ Can merge an array with other iterables (not just arrays).
	+ Supports newer JavaScript features.
* Cons:
	+ Introduced in ES6, which might not be supported in older browsers.
	+ May require more cognitive effort for developers unfamiliar with this feature.

**Other considerations:**

When choosing between `concat()` and the spread operator, consider:

1. **Browser support**: If you need to support older browsers (pre-ES6), use `Array.prototype.concat`.
2. **Performance**: In general, the spread operator is faster than `concat()`, as it avoids creating a new array.
3. **Code style**: Use the spread operator for its conciseness and expressive syntax, unless working with legacy code.

**Other alternatives?**

If you need to merge arrays in older browsers (pre-ES6), consider using:

1. **Concatenation via `push()` method**: Merge arrays by pushing elements from one array into another.
```javascript
var params = [ "hello", true, 7 ];
var other = [];
other.push(1);
other.push(2);
for (var i = 0; i < params.length; i++) {
    other.push(params[i]);
}
```
Keep in mind that this approach is less efficient and less readable than the spread operator. For modern browsers with ES6 support, stick with the spread operator for its conciseness and performance benefits.

This concludes our dive into the benchmark details!

Related benchmarks:

Array.prototype.concat vs spread operator test 34234 (version: 0)

Compare the new ES6 spread operator with the traditional concat() method

Comparing performance of: Array.prototype.concat vs spread operator

Created: 4 years ago by: Guest

Jump to the latest result

Array.prototype.concat

spread operator

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

Autogenerated LLM Summary (model llama3.1:latest, generated one year ago):