Benchmark: member vs proto member

Script Preparation code:

var A = class A {
	_aa = "_aa"
}

var B = class B extends A {}
var B2 = class B2 extends B {}
var B3 = class B3 extends B2 {}
var B4 = class B4 extends B3 {}
var B5 = class B5 extends B4 {}
var B6 = class B6 extends B5 {}
var B7 = class B7 extends B6 {}
var B8 = class B8 extends B7 {}
var B9 = class B9 extends B8 {}
var B10 = class B10 extends B9 {
	_bb = "_bb"
}

A.prototype._xx = "_xx"

var a = new B10()

console.log(a._aa, a._bb, a._xx)

Tests:

aa
var b = a._aa === "_aa"
bb
var b2 = a._bb === "_bb"
xx
var b3 = a._xx === "_xx"

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
aa
bb
xx

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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

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I'd be happy to explain what's being tested in this benchmark.

**Benchmark Overview**

The benchmark measures the performance difference between accessing properties using object prototypes versus literal property names. Specifically, it tests which approach is faster: accessing `_aa` and `_bb` through an object's prototype (using `A.prototype._xx`) or by directly accessing them as literal property names (`a._aa`, `a._bb`).

**Options Compared**

There are two approaches being compared:

1. **Prototype-based access**: Accessing properties using the prototype chain, i.e., `a._aa === "=_aa"`. This involves traversing the prototype chain to find the target property.
2. **Literal property access**: Directly accessing properties using literal property names, i.e., `a._bb === "_bb"`.

**Pros and Cons**

**Prototype-based access:**

Pros:

* Can be useful when working with objects that have a complex inheritance hierarchy or when you need to dynamically set property names.
* Can provide better support for polymorphism and dynamic method invocation.

Cons:

* Can be slower due to the overhead of traversing the prototype chain.
* May require more memory allocations and garbage collection, as each intermediate object in the prototype chain is created.

**Literal property access:**

Pros:

* Typically faster, as it avoids the overhead of traversing the prototype chain.
* Often results in better performance, as the compiler can optimize direct property accesses more effectively.

Cons:

* Limited to accessing properties directly on an object's literal name. This can be restrictive when working with complex objects or inheritance hierarchies.

**Considerations**

The choice between prototype-based access and literal property access depends on your specific use case and performance requirements. If you need to work with dynamic or polymorphic code, prototype-based access might be a better fit. However, if speed is critical, literal property access is often the way to go.

**Library Usage**

There is no explicit library usage mentioned in this benchmark. The test cases only involve basic JavaScript syntax and object creation.

**Special JS Features**

This benchmark does not use any special JS features or syntax beyond what's standard for JavaScript.

Related benchmarks:

member vs proto member (version: 0)

Comparing performance of: aa vs bb vs xx

Created: 2 years ago by: Registered User

Jump to the latest result

aa

bb

xx

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):