Benchmark: Spread Performance for Object & Arrays 2

Tests:

Object.assign
const object1 = { a: 1, b: 2, c: 3 }; const object2 = Object.assign({c: 4, d: 5}, object1);
Object spread
const object1 = { a: 1, b: 2, c: 3 }; const object2 = {c: 4, d: 5, ...object1};
Object Indexed Add
const object2 = {c: 4, d: 5}; object2["a"] = 1; object2["b"] = 2; object2["c"] = 3;
Object Dot Add
const object2 = {c: 4, d: 5}; object2.a = 1; object2.b = 2; object2.c = 3;
Array.prototype.concat
const array1 = [ "hello", true, 7 ]; const array2 = [ 1, 2 ].concat(array1);
Array.prototype.push (grouped)
const array1 = [ "hello", true, 7 ]; [ 1, 2 ].push("hello", true, 7)
Array.prototype.push (single)
const array1 = [ 1, 2 ] array1.push("hello") array1.push(true) array1.push(7)
Array Spread
const array1 = [ 1, 2 ] const array2 = ["hello", true, 7, ...array1]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.assign
Object spread
Object Indexed Add
Object Dot Add
Array.prototype.concat
Array.prototype.push (grouped)
Array.prototype.push (single)
Array Spread

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

The benchmark tests four different ways to perform object and array operations:

1. **Object Indexed Add**: This test measures the performance of assigning values to an object using square bracket notation (e.g., `object2["a"] = 1;`).
2. **Object Dot Add**: Similar to Object Indexed Add, but uses dot notation (e.g., `object2.a = 1;`).
3. **Array.prototype.push (single)**: This test measures the performance of pushing a single value onto an array using the `push()` method.
4. **Array.prototype.push (grouped)**: Similar to Array.prototype.push (single), but pushes multiple values onto an array at once.
5. **Object spread**: This test measures the performance of creating a new object by spreading an existing object's properties (e.g., `{...object1}`).
6. **Object assign**: This test measures the performance of assigning properties from one object to another using `Object.assign()`.
7. **Array Spread**: This test measures the performance of creating a new array by spreading an existing array's elements.

Now, let's discuss the pros and cons of each approach:

**Object Indexed Add and Object Dot Add**

* Both methods have similar performance characteristics, with dot notation generally being faster.
* The choice between dot and square bracket notation depends on personal preference and the specific use case.

**Array.prototype.push (single) and Array.prototype.push (grouped)**

* `push()` with multiple values can be slower due to the need for multiple function calls.
* However, some browsers may optimize this behavior, making it faster than pushing individual elements.
* The choice between single-element and grouped pushes depends on the specific use case.

**Object spread**

* This method can lead to slower performance due to the creation of a new object with multiple properties.
* However, modern browsers often optimize this behavior, making it competitive with other methods.

**Object assign**

* This method has generally slower performance compared to object spread and dot notation.
* The choice between `Object.assign()` and object spread depends on the specific use case.

In general, the performance differences between these methods are relatively small. However, when working with large datasets or performance-critical code, understanding these nuances can help optimize your code for better performance.

Keep in mind that these benchmarks may not reflect your specific use case, as browser optimizations and other factors can influence performance.

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.90 Safari/537.36

Browser/OS: Chrome 89 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Object.assign	5172089.0 Ops/sec
Object spread	14043076.0 Ops/sec
Object Indexed Add	931925824.0 Ops/sec
Object Dot Add	916660992.0 Ops/sec
Array.prototype.concat	3414842.0 Ops/sec
Array.prototype.push (grouped)	49943964.0 Ops/sec
Array.prototype.push (single)	50199008.0 Ops/sec
Array Spread	38363776.0 Ops/sec

Related benchmarks:

Spread Performance for Object & Arrays 2 (version: 1)

Comparing performance of: Object.assign vs Object spread vs Object Indexed Add vs Object Dot Add vs Array.prototype.concat vs Array.prototype.push (grouped) vs Array.prototype.push (single) vs Array Spread

Created: 5 years ago by: Registered User

Jump to the latest result

Object.assign

Object spread

Object Indexed Add

Object Dot Add

Array.prototype.concat

Array.prototype.push (grouped)

Array.prototype.push (single)

Array Spread

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):