Benchmark: func vs object vs symbol

Tests:

func(diff)
const a = function () { }; const b = function () { }; a === b;
func(eq)
const a = function () { }; const b = a; a === b;
obj(diff)
const a = {}; const b = {}; a === b;
obj(eq)
const a = {}; const b = a; a === b;
symbol(diff)
const a = Symbol("foo"); const b = Symbol("bar"); a === b;
symbol(eq)
const a = Symbol("foo"); const b = a; a === b;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
func(diff)
func(eq)
obj(diff)
obj(eq)
symbol(diff)
symbol(eq)

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/107.0.0.0 Safari/537.36

Browser/OS: Chrome 107 on Linux

View result in a separate tab

Test name	Executions per second
func(diff)	1412302464.0 Ops/sec
func(eq)	1415972480.0 Ops/sec
obj(diff)	1413015296.0 Ops/sec
obj(eq)	1411407488.0 Ops/sec
symbol(diff)	3891802.5 Ops/sec
symbol(eq)	7789917.0 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll explain the benchmark in detail, covering what's being tested, the pros and cons of each approach, and other considerations.

**Benchmark Overview**

The provided benchmark compares the performance of three different approaches:

1. **Function equality (eq)**: Comparing two functions using the `===` operator.
2. **Object equality (diff)**: Comparing two objects using a custom diff algorithm.
3. **Symbol equality (diff/symbol)** and **Symbol equality (eq)**: Comparing two symbols using a custom diff algorithm.

**What's being tested?**

The benchmark measures the performance of each approach by executing the following code:

* `const a = function () { };;` (Function literal)
* `const b = function () { };` (Another function literal)
* `a === b;` (Comparing two functions)

For object equality, it uses:
* `const a = {};`
* `const b = {};`
* `a === b;`

For symbol equality, it uses:
* `const a = Symbol("foo");`
* `const b = Symbol("bar");`
* `a === b;`

**Function Equality (eq)**

In JavaScript, when comparing two functions using `===`, the browser performs the following steps:

1. Creates an instance of `Function` for each function.
2. Compares the two instances using their property names and values.

Pros:

* Easy to implement, as it only requires a simple comparison.
* Works correctly even if the functions are not identical (e.g., one has more properties than the other).

Cons:

* Can lead to unexpected behavior due to the way `Function` instances are created and compared.
* Not suitable for objects or symbols.

**Object Equality (diff)**

The benchmark uses a custom diff algorithm to compare two objects. The idea is to find the differences between the two objects by comparing their property names and values.

Pros:

* Suitable for objects, as it takes into account all properties, including nested ones.
* Can be optimized for performance using efficient data structures and algorithms.

Cons:

* More complex to implement than function equality.
* May not work correctly if the objects have different types or data formats.

**Symbol Equality (diff/symbol)**

The benchmark uses a custom diff algorithm to compare two symbols. Symbols are unique, immutable properties of objects that cannot be reassigned.

Pros:

* Suitable for symbols, as it takes into account their unique, immutable nature.
* Can be optimized for performance using efficient data structures and algorithms.

Cons:

* More complex to implement than function equality or object equality.
* May not work correctly if the symbols have different formats or types.

**Symbol Equality (eq)**

For symbol equality, a simple comparison is performed:
```javascript
const a = Symbol("foo");
const b = a;
```
In this case, `a` and `b` are two references to the same symbol. The benchmark compares them using their raw value (`a === b`) rather than comparing them as objects.

Pros:

* Simple implementation.
* Works correctly even if the symbols have different formats or types.

Cons:

* Not suitable for objects or functions, which may not behave consistently with symbols.

**Other Considerations**

When running this benchmark, consider the following factors that can impact performance:

* **Cache locality**: The way browsers cache and reuse memory can affect performance. Functions and objects with similar names or properties might be stored in adjacent memory locations.
* **Type coercion**: When comparing values using `===`, JavaScript performs type coercion. This can lead to unexpected behavior if the types are not what you expect.
* **Symbol implementation**: Symbols are a relatively new feature, and their implementation may vary between browsers.

**Alternatives**

If you're interested in exploring alternative approaches or optimizing your benchmark, consider the following:

* **Use `Object.is()` instead of `===` for object comparison**: This function is specifically designed for comparing objects and provides better performance.
* **Use a dedicated diff algorithm library**: There are libraries available that provide efficient implementations for comparing objects and symbols.
* **Experiment with different browsers and environments**: The benchmark results may vary depending on the specific browser or environment being used.

Related benchmarks:

func vs object vs symbol (version: 0)

Comparing performance of: func(diff) vs func(eq) vs obj(diff) vs obj(eq) vs symbol(diff) vs symbol(eq)

Created: 2 years ago by: Registered User

Jump to the latest result

func(diff)

func(eq)

obj(diff)

obj(eq)

symbol(diff)

symbol(eq)

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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