Benchmark: new instance versus direct assignment

Tests:

direct assignment
class Vector2 { constructor(x, y) { this.x = x; this.y = y; } } var a = new Vector2(0, 0); for(i=0; i<10000; i++){ a.x = i; a.y = i; }
new instance
class Vector2 { constructor(x, y) { this.x = x; this.y = y; } } var a = new Vector2(0, 0); for(i=0; i<10000; i++){ a = new Vector2(i,i); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
direct assignment
new instance

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 break down the provided benchmark test cases.

**Benchmark Definition**

The benchmark is designed to compare two approaches: creating a new instance of an object versus directly assigning values to existing properties.

In JavaScript, objects are created using constructors (e.g., `new Vector2(0, 0)`), and properties can be accessed and modified using dot notation (e.g., `a.x = i;`).

**Options Compared**

Two options are being compared:

1. **Direct Assignment**: Creating a new instance of the object and assigning values to its properties using dot notation.
```javascript
var a = new Vector2(0, 0);
for(i=0; i<10000; i++) {
  a.x = i;
  a.y = i;
}
```
2. **New Instance**: Creating a new instance of the object and assigning values to its properties using dot notation.
```javascript
var a = new Vector2(0, 0);
for(i=0; i<10000; i++) {
  a = new Vector2(i,i);
}
```

**Pros and Cons**

1. **Direct Assignment**:
	* Pros: Can be faster since it avoids the overhead of creating a new instance.
	* Cons: May lead to confusion or errors if not used carefully, as the original object's properties are modified instead of creating a new copy.
2. **New Instance**:
	* Pros: Creates a new, independent copy of the object, which can be beneficial for thread safety or when working with mutable objects.
	* Cons: Can be slower due to the overhead of creating a new instance.

**Library**

The `Vector2` class is not a built-in JavaScript library but rather a custom implementation. It's likely used here to demonstrate the benchmarking scenario in a more controlled environment.

**Special JS Features/Syntax**

None are explicitly mentioned or required for this benchmark.

**Other Considerations**

When choosing between direct assignment and creating new instances, consider the following:

* If you need to work with mutable objects that should be thread-safe or independent, use the `new` instance approach.
* If you're working with immutable objects or performance-critical code where speed is paramount, direct assignment might be a better choice.

**Alternatives**

For benchmarking JavaScript performance, other alternatives include:

1. Microbenchmarking libraries like `fast-math`, `micro-benchmark`, or `benchmark.js`.
2. Built-in browser APIs for measuring execution time, such as `performance.now()` or `PerformanceObserver`.
3. Other JavaScript profiling tools, like `Chrome DevTools` or `Firefox Developer Edition`.

Related benchmarks:

new instance versus direct assignment (version: 0)

Comparing performance of: direct assignment vs new instance

Created: 4 years ago by: Registered User

Jump to the latest result

direct assignment

new instance

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):