Benchmark: Object.assign vs spread operator 21414

Tests:

Object.assign
var params = { b:"hello", c: true, d:7 }; var other = Object.assign({ a: 2 }, params);
spread operator
var params = { b:"hello", c: true, d:7 }; var other = { a: 2, ...params };

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.assign
spread operator

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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Let's break down the provided JSON data and explain what is being tested, compared, and the pros and cons of each approach.

**Benchmark Definition**

The benchmark is comparing two approaches to merge objects in JavaScript:

1. `Object.assign()`
2. Spread operator (`...`)

**Test Cases**

There are two test cases:

1. **Object.assign**: This test case creates an object with properties `a`, `b`, and `c`. It then uses the `Object.assign()` method to merge this object with another object `params`.
```javascript
var params = { b: "hello", c: true, d: 7 };
var other = Object.assign({ a: 2 }, params);
```
The purpose of this test case is to measure the performance of `Object.assign()` in merging objects.

2. **Spread Operator**: This test case creates an object with properties `a`, `b`, and `c`. It then uses the spread operator (`...`) to merge this object with another object `params`.
```javascript
var params = { b: "hello", c: true, d: 7 };
var other = { a: 2, ...params };
```
The purpose of this test case is to measure the performance of the spread operator in merging objects.

**Library/ Framework**

Neither of these test cases uses any external libraries or frameworks. The only JavaScript features being tested are the `Object.assign()` method and the spread operator (`...`).

**Special JS Features/Syntax**

There is no special JS feature or syntax being tested here. However, it's worth noting that the spread operator is a relatively new feature in JavaScript (introduced in ECMAScript 2018), so some older browsers may not support it.

**Other Alternatives**

If you were to compare these two approaches using other methods, you might consider:

* Using `Object.create()` and assigning properties
* Using a loop to iterate over the properties of `params` and assign them to `other`
* Using a library like Lodash's `assign` function

However, in most cases, the spread operator is a concise and efficient way to merge objects, making it a popular choice.

**Pros and Cons**

Here are some pros and cons of each approach:

**Object.assign()**

Pros:

* Wide support across older browsers
* Simple and straightforward syntax
* Can be used with arrays and other types of objects

Cons:

* Can be slower than the spread operator for large objects
* May create new object references, which can lead to memory allocation issues in some cases

**Spread Operator**

Pros:

* Concise and expressive syntax
* Fast performance
* Works with arrays and other types of objects

Cons:

* Limited support across older browsers (introduced in ECMAScript 2018)
* Can be less readable for developers who are not familiar with the spread operator

Overall, the spread operator is a good choice when you need to merge objects in modern JavaScript environments. However, if you need to support older browsers or have specific requirements that require `Object.assign()`, it's still a viable option.

Related benchmarks:

Object.assign vs spread operator 21414 (version: 0)

Comparing performance of: Object.assign vs spread operator

Created: 7 years ago by: Guest

Jump to the latest result

Object.assign

spread operator

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):