Benchmark: JavaScript spread operator vs Object declaration

Tests:

Using the spread operator
const finalObject = { "CUBE_": "1", "DIMENSION": "Test", "MEMBER": "TestMember", "READ": true, "WRITE": true };
Using Object.assign
const firstObject = { "CUBE_": "1", "DIMENSION": "Test", "MEMBER": "TestMember", }; const secondObject = { "READ": true, "WRITE": true } const finalObject = Object.assign(firstObject, secondObject);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Using the spread operator
Using Object.assign

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

**Benchmark Definition**

The benchmark is comparing two approaches to create an object in JavaScript: using the spread operator (`...`) and `Object.assign()`.

**Script Preparation Code**

There is no script preparation code provided, which means that the test cases are likely creating the objects from scratch without any additional setup or initialization.

**Individual Test Cases**

There are two test cases:

1. **Using the spread operator**: This test case uses the spread operator (`...`) to create a new object by copying properties from an existing object (`firstObject`). The code is: `const finalObject = { ...firstObject, "READ": true, "WRITE": true };`
2. **Using Object.assign()**: This test case uses the `Object.assign()` method to merge two objects: `firstObject` and a new object (`secondObject`) that only contains some properties (`"READ": true`, `"WRITE": true`). The code is: `const finalObject = Object.assign(firstObject, secondObject);`

**What's being tested?**

The test is comparing the performance of these two approaches to create an object with some common properties. The benchmark likely measures how many executions per second each approach can perform.

**Options compared**

The two options being compared are:

1. Using the spread operator (`...`)
2. Using `Object.assign()`

**Pros and Cons:**

* **Using the spread operator (`...`):**
	+ Pros:
		- Can be used to create a new object with some common properties from an existing object.
		- Often more concise and readable than using `Object.assign()`.
	+ Cons:
		- May not be as efficient as using `Object.assign()` if the number of properties is large.
* **Using Object.assign():**
	+ Pros:
		- Can be used to merge multiple objects into one.
		- Often more efficient than using the spread operator when dealing with a large number of properties.
	+ Cons:
		- May not be as concise or readable as using the spread operator.

**Other considerations:**

* The use of `Object.assign()` might involve some additional overhead due to the method call and potential checks for null or undefined values being assigned.
* Using the spread operator might involve some additional overhead due to the need to create a new object and iterate over its properties.

**Library/Functionality usage:**

In this benchmark, we're using built-in JavaScript functionality:

* `Object.assign()`: a method on the `Object` class that merges two or more objects into one.
* Spread operator (`...`): a syntax feature introduced in ECMAScript 2018 that allows creating new objects by copying properties from an existing object.

**Special JS feature/syntax:**

The spread operator is a special JavaScript feature, also known as the "rest and spread operator". It was introduced in ECMAScript 2015 (ES6) to provide a concise way to create new objects or arrays with some common properties.

Related benchmarks:

JavaScript spread operator vs Object declaration (version: 0)

Comparing performance of: Using the spread operator vs Using Object.assign

Created: 2 years ago by: Guest

Jump to the latest result

Using the spread operator

Using 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):