Benchmark: Object.assign vs SPREAD vs lodash assignIn

HTML Preparation code:

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.js"></script>

Script Preparation code:

var foo = {}
for (var i=0;i<100;i++) {
    foo['foo'+i] = i;
    foo['bar'+i] = i;
    foo['foobar'+i] = i;
}

var bar = {}
for (var i=0;i<100;i++) {
    bar['bar'+i] = i;
    bar['foo'+i] = i;
    bar['barfoo'+i] = i;
}

Tests:

Object.assign()
Object.assign({}, foo, bar)
SPREAD operator
var a = {...foo, ...bar}
Lodash assignIn
_.assignIn({}, foo, bar)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.assign()
SPREAD operator
Lodash assignIn

Fastest: N/A

Slowest: N/A

Latest run results:

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

LLMs can make mistakes. Check important info.

**Benchmark Overview**

The provided benchmark is designed to compare the performance of three different methods for merging objects: `Object.assign()`, the SPREAD operator (`...`), and `lodash.assignIn()`.

**Options Compared**

The benchmark compares the execution speed of these three methods on a large dataset consisting of two objects, `foo` and `bar`, each containing 100 properties. The objects are created using nested loops in the `Script Preparation Code`.

* `Object.assign()`: A built-in JavaScript method for merging objects.
* SPREAD operator (`...`): A syntax sugar for creating a new object from an existing one.
* `lodash.assignIn()`: A function from the Lodash library that merges objects, allowing for specifying a path to update.

**Pros and Cons of Each Approach**

1. **Object.assign()**:
	* Pros: Widely supported, simple to use, and efficient in most cases.
	* Cons: Can be slower than other methods when dealing with large datasets or deep object structures.
2. **SPREAD operator (`...`)**:
	* Pros: Simple to use, concise syntax, and relatively fast for small to medium-sized objects.
	* Cons: Can lead to slower performance when dealing with very large objects or complex merges.
3. **Lodash.assignIn()**:
	* Pros: Allows for more control over the merge process (e.g., specifying a path), can be faster than `Object.assign()` for large datasets, and provides a fallback mechanism for missing keys.
	* Cons: Requires an additional library import, which may introduce latency or overhead.

**Library: Lodash**

Lodash is a popular JavaScript utility library that provides a wide range of functions for working with data structures, such as arrays, objects, and more. The `assignIn()` function is part of the Lodash library's object manipulation suite.

**Special JS Feature/Syntax**

The SPREAD operator (`...`) is a syntax sugar introduced in ECMAScript 2015 (ES6) to create new objects from existing ones. It allows for a more concise way to merge objects using the `...` spread notation, e.g., `var obj = {...foo, ...bar}`.

**Other Alternatives**

* **Object.assign()` with an object literal**: Instead of using the spread operator, you can use the `Object.assign()` method with an object literal to achieve similar results: `var obj = Object.assign({}, foo, bar)`.
* **Array.prototype.reduce()**: Another way to merge objects is by using the `Array.prototype.reduce()` method. For example: `var obj = reduce((acc, val) => ({...acc, ...val}), {}, [foo, bar])`.

In conclusion, the benchmark highlights the importance of choosing the most efficient merging strategy for your specific use case, taking into account factors like object size, complexity, and performance requirements.

Related benchmarks:

Object.assign vs SPREAD vs lodash assignIn (version: 0)

Comparing performance of: Object.assign() vs SPREAD operator vs Lodash assignIn

Created: 8 years ago by: Guest

Jump to the latest result

Object.assign()

SPREAD operator

Lodash assignIn

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):