Benchmark: initializeFromJson

Tests:

init from json
const a = { x: 'xxx', y: 1, z: null } const b = { z: 1, u: 'uuu', v: null } for (let prop in Reflect.ownKeys(b)) a[prop] = b[prop];
object.assign
const a = { x: 'xxx', y: 1, z: null } const b = { z: 1, u: 'uuu', v: null } Object.assign(a, b)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
init from json
object.assign

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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I'd be happy to help explain the benchmark and its results.

**Benchmark Overview**

The provided benchmark measures the performance of two approaches: `for...in` loop with `Reflect.ownKeys()` versus `Object.assign()`. The benchmark definition is represented by JSON, which includes a script preparation code that initializes two objects, `a` and `b`, with some properties. The script then uses a `for...in` loop to iterate over the own keys of object `b` and assigns the corresponding property values from `b` to `a`. Alternatively, it uses the `Object.assign()` method to achieve the same result.

**Options Compared**

The benchmark compares two approaches:

1. **For...in loop with Reflect.ownKeys()**: This approach uses a traditional `for...in` loop with the `Reflect.ownKeys()` function to iterate over the own keys of object `b`.
2. **Object.assign()**: This approach uses the `Object.assign()` method to assign property values from object `b` to object `a`.

**Pros and Cons**

*   For...in loop with Reflect.ownKeys():
    *   Pros:
        *   Less memory allocation is required since it only iterates over own keys.
        *   Can be more efficient in certain scenarios where the number of properties is limited.
    *   Cons:
        *   May have slower performance due to the overhead of using `Reflect.ownKeys()`.
*   Object.assign():
    *   Pros:
        *   More concise and readable code.
        *   Often faster since it uses optimized native code under the hood.
    *   Cons:
        *   May require more memory allocation, especially when dealing with large objects.

**Other Considerations**

When choosing between these approaches, consider the following factors:

*   Code readability: If you prioritize concise and readable code, `Object.assign()` might be a better choice. However, if you want to explicitly iterate over own keys for clarity or performance reasons, the `for...in` loop with `Reflect.ownKeys()` is an option.
*   Performance: In general, `Object.assign()` tends to be faster due to its native implementation. Nevertheless, this may not always be the case, and the choice ultimately depends on your specific use case.

**Library/Functionality Used**

In the benchmark definition, the following functionality/libraries are used:

*   **Reflect**: A JavaScript object that provides utility functions for working with objects, including `ownKeys()`.
*   **Object.assign()**: A built-in JavaScript method for copying properties from one or more source objects to a target object.

**Special JS Feature/Syntax**

In this benchmark, the following special feature/syntax is used:

*   **`Reflect.ownKeys()`**: This function returns an iterator that yields only the own property names of an object.
*   **Object.assign()**: While not strictly a "special" feature, `Object.assign()` uses optimized native code under the hood, which can impact performance.

**Alternatives**

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

*   Use other iteration methods (e.g., `for...of`, `forEach()`, `Array.prototype.forEach()`).
*   Experiment with different data structures (e.g., using arrays instead of objects).
*   Compare performance with other JavaScript engines or browsers.
*   Optimize code for specific use cases, such as reducing memory allocation or minimizing function calls.

Related benchmarks:

initializeFromJson (version: 0)

Comparing performance of: init from json vs object.assign

Created: 3 years ago by: Guest

Jump to the latest result

init from json

object.assign

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):