Benchmark: merge vs set a value

Tests:

merge
let obj1 = { first: 'first', second: 'second', third: 'third' }; const obj2 = { fourth: 'fourth' }; obj1 = { ...obj1, ...obj2, };
set a value
let obj1 = { first: 'first', second: 'second', third: 'third' }; obj1.fourth = 'fourth';

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
merge
set a value

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.112 Safari/537.36

Browser/OS: Chrome 86 on Linux

View result in a separate tab

Test name	Executions per second
merge	226649.4 Ops/sec
set a value	74262248.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark and explain what's being tested.

**Benchmark Overview**

The benchmark is designed to compare two approaches: merging objects using the spread operator (`...`) versus setting a value on an existing object.

**Options Compared**

Two options are compared:

1. **Merge**: Using the spread operator to merge two objects, `obj1` and `obj2`. This approach creates a new object with all properties from both objects.
2. **Set a value**: Setting a single property (`fourth`) on an existing object (`obj1`). This approach modifies the original object by assigning a new value to the specified property.

**Pros and Cons of Each Approach**

**Merge:**

Pros:

* Can be more efficient for large objects with many properties, as it avoids creating a temporary object.
* Can be more readable for complex merge scenarios.

Cons:

* Creates a new object, which may incur additional memory allocation overhead.
* May not be as intuitive for simple assignment cases.

**Set a Value:**

Pros:

* Modifies the original object, avoiding unnecessary memory allocations.
* Suitable for simple assignment cases.

Cons:

* Can lead to unexpected behavior if the property is already present in the original object and has a different data type.
* May not be as efficient for large objects with many properties.

**Library and Special JS Features**

There doesn't seem to be any specific library being used in this benchmark. However, it's worth noting that `let` declarations are commonly used in modern JavaScript code, and the syntax is generally considered idiomatic.

**Other Considerations**

* **Object Literal Syntax**: The benchmark uses a simple object literal syntax, which is widely supported by modern browsers.
* **Browser Support**: The benchmark appears to be optimized for desktop browsers (Chrome 86 on Linux) but may not work as expected in other environments.

**Alternatives**

If you're looking for alternative approaches or variations on this benchmark, consider the following:

* Compare the performance of different merge strategies, such as using `Object.assign()` instead of the spread operator.
* Test the impact of using `const` vs. `let` declarations on object assignments.
* Examine the performance of other property assignment methods, like using `this[propertyName] = value;`.

Keep in mind that these variations may require additional setup and configuration for the benchmark to work correctly.

I hope this explanation helps you understand what's being tested in MeasureThat.net!

Related benchmarks:

merge vs set a value (version: 0)

Comparing performance of: merge vs set a value

Created: 5 years ago by: Guest

Jump to the latest result

merge

set a value

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):