Benchmark: Object Assign vas Spread vs Map

Tests:

Spread
const firstObject = { sampleData: 'Hello world' } const secondObject = { moreData: 'foo bar' } const finalObject = { ...firstObject, ...secondObject };
Object Assign
const firstObject = { sampleData: 'Hello world' } const secondObject = { moreData: 'foo bar' } const finalObject = Object.assign({}, firstObject, secondObject);
Map
const firstMap = new Map([ ['key', 'value'] ]) const secondMap = new Map([ ['key2', 'value2'] ]) const finalMap = new Map([...firstMap, ...secondMap])

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Spread
Object Assign
Map

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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**Overview**

The provided benchmark measures the performance of three different methods for merging objects or arrays in JavaScript: using the spread operator (`...`), `Object.assign()`, and creating a new Map instance with the `Map()` constructor.

**Benchmark Definitions**

There are two main types of benchmark definitions:

1. **Individual test cases**: Each test case has a unique name, description, script preparation code, HTML preparation code (which is empty in this case), and a benchmark definition that describes the specific operation being measured.
2. **The benchmark suite as a whole**: This includes three individual test cases with different methods for merging objects or arrays.

**Test Cases**

There are three test cases:

1. **"Object Assign"`:
	* Benchmark definition: `const firstObject = { sampleData: 'Hello world' }\r\nconst secondObject = { moreData: 'foo bar' }\r\nconst finalObject = Object.assign({}, firstObject, secondObject);`
	* Purpose: Measure the performance of using `Object.assign()` to merge two objects.
2. **"Spread"`:
	* Benchmark definition: `const firstObject = { sampleData: 'Hello world' }\r\nconst secondObject = { moreData: 'foo bar' }\r\nconst finalObject = {\r\n\t...firstObject,\r\n  \t...secondObject\r\n};`
	* Purpose: Measure the performance of using the spread operator (`...`) to merge two objects.
3. **"Map"`:
	* Benchmark definition: `const firstMap = new Map([ ['key', 'value']  ])\r\nconst secondMap = new Map([ ['key2', 'value2']  ])\r\nconst finalMap = new Map([...firstMap, ...secondMap])`
	* Purpose: Measure the performance of using a Map instance to merge two collections of key-value pairs.

**Options Compared**

The three methods are compared in terms of their execution time:

1. **`Object.assign()`**: Uses the `Object.assign()` method to merge two objects.
2. **Spread operator (`...`)**: Uses the spread operator (`...`) to merge two objects.
3. **Map instance**: Uses a Map instance to merge two collections of key-value pairs.

**Pros and Cons**

Here's a brief summary of the pros and cons of each approach:

1. **`Object.assign()`**:
	* Pros: Wide support, simple syntax.
	* Cons: Can be slow for large objects, may not preserve prototype chain.
2. **Spread operator (`...`)**:
	* Pros: Simple syntax, good performance for small to medium-sized objects.
	* Cons: May not work as expected with certain data structures or libraries.
3. **Map instance**:
	* Pros: Good performance for large collections, preserves key-value pairs and prototype chain.
	* Cons: May have higher memory overhead due to the Map instance.

**Library Used**

None of the benchmark cases use a specific library. However, the `Map` instance test case uses the built-in `Map()` constructor, which is part of the ECMAScript standard.

**Special JavaScript Feature or Syntax**

The spread operator (`...`) was introduced in ECMAScript 2015 (ES6) and is a relatively new feature in JavaScript.

**Other Alternatives**

If you need to merge objects or arrays in JavaScript, other alternatives include:

1. **`Object.create()`**: Creates a new object with the specified prototype chain.
2. **`Array.prototype.concat()`**: Concatenates two arrays into a single array.
3. **`JSON.parse(JSON.stringify(obj))`**: A more complex approach that uses JSON parsing to merge objects.

However, these alternatives may have higher overhead or different performance characteristics compared to the methods being benchmarked.

Related benchmarks:

Object Assign vas Spread vs Map (version: 0)

Comparing performance of: Spread vs Object Assign vs Map

Created: 3 years ago by: Guest

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Spread

Object Assign

Map

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):