Benchmark: Array.prototype.concat vs spread operator(push)

Script Preparation code:

var arr = Array(100).fill([{n: ''}]);

Tests:

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

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.prototype.concat
spread operator
array.push

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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Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

**Benchmark Overview**

The benchmark compares three approaches for concatenating an array in JavaScript:

1. **Array.prototype.concat**: The traditional method using the `concat()` function.
2. **Spread operator (push)**: A new ES6 feature that uses the spread operator (`...`) to concatenate arrays.
3. **array.push**: An alternative approach that pushes elements onto the end of the array.

**Options Compared**

The benchmark tests each option on a sample dataset:

* `arr` is an array of 100 objects with a single property `n`.
* `params` is an array containing three values: "hello", `true`, and `7`.

The benchmark measures the performance of each approach in terms of executions per second.

**Pros and Cons**

Here's a brief summary of each approach:

1. **Array.prototype.concat**:
	* Pros: Wide browser support, easy to use.
	* Cons: Can be slow for large arrays due to the overhead of creating a new array object.
2. **Spread operator (push)**:
	* Pros: Fast and efficient for small to medium-sized arrays. New feature in ES6.
	* Cons: Limited browser support, may require ES6 transpilation for older browsers.
3. **array.push**:
	* Pros: Fast and efficient, especially for large arrays.
	* Cons: May not be as readable or maintainable as the other two options.

**Library Usage**

There is no explicit library usage in this benchmark. However, it's worth noting that modern JavaScript engines often provide additional optimizations and features that may affect performance, such as Just-In-Time (JIT) compilation or garbage collection.

**Special JS Features or Syntax**

The spread operator (`...`) was introduced in ES6 and provides a concise way to concatenate arrays. The syntax is `arr.push(...params)`.

**Other Alternatives**

Some other approaches for concatenating arrays include:

1. **Array.prototype.reduce()**: A more functional approach that uses the reduce() method to accumulate elements into an array.
2. **Array.prototype.forEach()**: While not a traditional concatenation method, you can use forEach() with a callback function to concatenate elements.

However, these alternatives are not tested in this benchmark, and their performance may vary depending on the specific use case.

**Benchmark Results**

The latest benchmark results show that:

1. `array.push` is the fastest approach, followed by the spread operator (`...`) and then `Array.prototype.concat`.
2. Chrome 74 is the only browser used for testing.
3. The executions per second values suggest a relatively fast execution time for each approach.

Keep in mind that benchmark results may vary depending on specific use cases, hardware, and software configurations.

Related benchmarks:

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

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

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

Created: 7 years ago by: Guest

Jump to the latest result

Array.prototype.concat

spread operator

array.push

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):