Benchmark: Spread operator vs apply new

Script Preparation code:

function test() { console.log(arguments[arguments.length - 1]); }
var using = (new Array(200)).fill(null).map((e, i) => (i));
var using2 = (new Array(200)).fill(null).map((e, i) => (i));

Tests:

spread
test(...using, ...using2);
apply
test.apply(using2, using)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
spread
apply

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.

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

**Benchmark Overview**

The benchmark compares two ways to call a function with arbitrary arguments dynamically: using the spread operator (`...`) and `apply()`. The test creates an array of 200 elements, fills it with null values, and maps over it to generate two arrays, `using` and `using2`, which are then passed as arguments to the `test()` function.

**Options Compared**

The benchmark compares two options:

1. **Spread Operator (`...`)**: This method uses the spread operator to pass an array of arguments to a function.
```javascript
function test(...args) { console.log(args); }
var using = (new Array(200)).fill(null).map((e, i) => (i));
test(...using);
```
Pros:

* Concise and expressive syntax.
* Easy to read and write.

Cons:

* May not be optimized by some JavaScript engines for performance-critical code.

2. **`apply()` Method**: This method uses the `apply()` function to pass an array of arguments to a function.
```javascript
function test() { console.log(arguments[arguments.length - 1]); }
var using = (new Array(200)).fill(null).map((e, i) => (i));
test.apply(using);
```
Pros:

* Allows for more control over the argument order and can be used in performance-critical code.

Cons:

* Less concise syntax than spread operator.
* May require more manual memory management.

**Library Used**

The `fill()` method is used to create an array of 200 null values. The purpose of this library is to provide a convenient way to initialize arrays with specific values.

**Special JavaScript Features/Syntax**

None mentioned in the benchmark definition.

**Other Considerations**

When deciding between using the spread operator and `apply()`, consider the following:

* **Readability**: If code readability is more important than performance, use the spread operator.
* **Performance**: If performance is critical, use `apply()` to gain more control over the argument order.
* **Compatibility**: Some older JavaScript engines may not support the spread operator or have different behavior.

**Alternatives**

Other alternatives for passing arguments dynamically include:

1. `Rest Parameters (`...args`)`: Introduced in ECMAScript 2015 (ES6), this method uses rest parameters to pass an array of arguments to a function.
2. `Function Expressions with `this` Bindings**: This method uses function expressions and the `this` binding to pass arguments dynamically.

For example:
```javascript
function test(a, b) { console.log(a, b); }
var using = (new Array(200)).fill(null).map((e, i) => ({ a: e, b: i }));
test(...using.map(obj => obj.a), ...using.map(obj => obj.b));
```
However, these alternatives may not be as concise or efficient as the spread operator or `apply()`.

I hope this explanation helps you understand the JavaScript microbenchmark on MeasureThat.net!

Related benchmarks:

Spread operator vs apply new (version: 0)

Compare the differing ways you can call a function with arbitrary arguments dynamically

Comparing performance of: spread vs apply

Created: 5 years ago by: Guest

Jump to the latest result

spread

apply

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):