Benchmark: javascript concat vs spread operator vs push1231231000

Script Preparation code:

var existed =new Array(10000).map(x => 1);

Tests:

spread operator
var params = [ "hello", true, 7 ]; var other = [ ...existed, ...params ];
spread operator2
var params = [ "hello", true, 7 ]; var clone = [ ...existed ]; var other = clone.push(...params);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
spread operator
spread operator2

Fastest: N/A

Slowest: N/A

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

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**Benchmark Overview**

MeasureThat.net provides a platform for JavaScript microbenchmarks, allowing users to compare the performance of different approaches and libraries in executing specific tasks.

The benchmark you provided tests three approaches:

1. **Concatenation (using the `...` operator)**: This approach uses the spread operator (`...`) to concatenate two arrays.
2. **Push with Spread Operator**: This approach uses the `push()` method with the spread operator (`...`) to add elements to an array.
3. **Concatenation (using `new Array()` and `push()`)**: This approach creates a new array and pushes elements onto it using the `push()` method.

**Options Comparison**

Here's a brief overview of each approach:

*   **Concatenation with Spread Operator (`...`)**: This is often considered the most efficient way to concatenate arrays in modern JavaScript. The spread operator is implemented in V8 (Google Chrome's JavaScript engine) and is highly optimized.
*   **Push with Spread Operator**: While this approach uses a similar syntax to concatenation, it creates an intermediate array that needs to be pushed into another array. This can lead to slower performance compared to direct concatenation using the spread operator.
*   **Concatenation with `new Array()` and `push()`**: This approach requires creating a new array and pushing elements onto it using the `push()` method. While this approach is more straightforward, it's often slower than other methods due to the overhead of creating an intermediate array.

**Pros and Cons**

Here are some pros and cons for each approach:

*   **Concatenation with Spread Operator (`...`)**:
    *   Pros: Fast execution, widely supported by modern browsers.
    *   Cons: May not work as expected in older browsers that don't support the spread operator.
*   **Push with Spread Operator**:
    *   Pros: Easy to read and write code, works in older browsers.
    *   Cons: Creates an intermediate array, slower than direct concatenation.
*   **Concatenation with `new Array()` and `push()`**:
    *   Pros: Simple and easy to understand.
    *   Cons: Slower due to the overhead of creating an intermediate array.

**Library Usage**

The benchmark uses the `existed` variable, which is created using the following JavaScript code:

```javascript
var existed = new Array(10000).map(x => 1);
```

This creates a new array with 10,000 elements and initializes each element to 1. The spread operator (`...`) is used later in the benchmark to concatenate this array with another array.

**Special JS Features/Syntax**

The benchmark uses the following special JavaScript features:

*   **Spread Operator (`...`)**: This feature was introduced in ECMAScript 2015 (ES6) and allows arrays or objects to be expanded into a new array or object.
*   **Template Literals**: The backticks (`"..."`) used to define strings are part of the template literals syntax, which was also introduced in ES6.

**Alternative Approaches**

If you need to compare performance for other approaches, here are some alternatives:

*   **Array.prototype.concat()**: This method concatenates two or more arrays and returns a new array.
*   **Array.prototype.push()**: This method adds one or more elements to the end of an array.
*   **Array.prototype.slice()**: This method creates a shallow copy of a portion of an array.

These alternative approaches may have different performance characteristics depending on the specific use case, so be sure to test and benchmark them as needed.

Related benchmarks:

javascript concat vs spread operator vs push1231231000 (version: 0)

javascript concat vs spread operator vs push

Comparing performance of: spread operator vs spread operator2

Created: 3 years ago by: Guest

Jump to the latest result

spread operator

spread operator2

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):