Benchmark: test modify reference vs Object destructing

Tests:

reference
function test() { const obj = {c: 3, d: 9, a: 2} obj.a = 4 return obj; } test();
Object destructing
function test() { const obj = {c: 3, d: 9, a: 2} return {...obj, a: 4} } test();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
reference
Object destructing

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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I'll explain the benchmark in detail, covering what's being tested, the options compared, pros and cons of each approach, library usage, special JavaScript features, and other considerations.

**Benchmark Overview**

The benchmark is designed to compare the performance of two approaches: reference assignment (`obj.a = 4`) and object destructuring (`return {...obj, a: 4}`).

**Options Compared**

Two options are being compared:

1. **Reference Assignment**: `obj.a = 4` This approach modifies the original object by assigning a new value to one of its properties.
2. **Object Destructuring**: `return {...obj, a: 4}` This approach creates a new object by copying all properties from the original object (`obj`) and then adds a new property (`a: 4`). The resulting object is returned.

**Pros and Cons**

### Reference Assignment

Pros:

* Efficient in terms of memory allocation (no new object creation)
* Can be faster since it doesn't involve object creation and copying

Cons:

* Modifies the original object, which might not be intended behavior
* Can lead to unexpected side effects if the object is used elsewhere in the code

### Object Destructuring

Pros:

* Creates a new object, ensuring that the original object remains unchanged
* Allows for more predictable behavior since it creates a fresh copy of the object

Cons:

* Involves additional memory allocation and object creation
* Might be slower due to these overheads

**Library Usage**

There is no explicit library usage in this benchmark. However, the `Object.assign()` method is implicitly used when comparing reference assignment.

**Special JavaScript Features**

None are explicitly mentioned in this benchmark.

**Other Considerations**

1. **Memory allocation**: Both approaches allocate memory, but object destructuring might incur additional overhead due to object creation and copying.
2. **Cache performance**: The results suggest that Chrome 115 on a Mac OS X 10.15.7 machine performs better for reference assignment. This might be due to cache performance or other factors specific to this browser environment.
3. **Interpretation of results**: When interpreting the benchmark results, consider the trade-offs between performance and code readability. Object destructuring provides a more predictable behavior, but it comes with additional overhead.

**Alternatives**

Other alternatives for comparing object modification performance might include:

* Using a different property assignment method (e.g., `obj.a = 4; obj.b = 5`)
* Comparing the performance of other JavaScript features, such as array creation or function invocation
* Evaluating the impact of various browsers, engines, or platforms on benchmark results

Related benchmarks:

test modify reference vs Object destructing (version: 0)

reference vs Object destructing which high performance

Comparing performance of: reference vs Object destructing

Created: 2 years ago by: Guest

Jump to the latest result

reference

Object destructing

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):