Benchmark: object: assign vs spread

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 };

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Suite status: <idle, ready to run>

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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 benchmark and explain what's being tested.

**What is being tested?**

The provided JSON represents two individual test cases, comparing the performance of two approaches for assigning properties to an object in JavaScript:

1. **`Object.assign()`**: This method creates a new object by copying all enumerable own properties from one or more source objects into a new object.
2. **Spread operator (`...`)**: This syntax allows you to expand an object (or any other iterable) into individual properties of another object.

**Options compared**

The two approaches being tested are:

1. `Object.assign()`: A method that creates a new object by copying properties from the provided source objects.
2. Spread operator: An operator that expands an object's properties into individual assignments to a target object.

**Pros and Cons of each approach**

1. **`Object.assign()`**:
	* Pros:
		+ Simple and concise syntax
		+ Well-documented and widely supported
	* Cons:
		+ Creates a new object, which can be memory-intensive for large datasets
		+ May not be as efficient as other approaches for very large datasets
2. **Spread operator (`...`)**:
	* Pros:
		+ More readable syntax (some might find it more intuitive)
		+ Can be more concise than `Object.assign()` for simple cases
	* Cons:
		+ Less widely supported in older browsers or environments
		+ May not be as performant as other approaches, especially for large datasets

**Library and purpose**

There is no library mentioned in the provided code. The `Object.assign()` method is a built-in JavaScript method.

**Special JS feature or syntax**

The spread operator (`...`) is a relatively new syntax introduced in ECMAScript 2015 (ES6). It allows you to expand an object's properties into individual assignments to another object.

**Other alternatives**

If you're looking for alternative approaches, consider the following:

1. **`for...in` loop**: You can use a `for...in` loop to iterate over the source object's properties and assign them to the target object.
```javascript
var target = {};
for (var key in params) {
  target[key] = params[key];
}
```
2. **Array methods**: If you're working with arrays, you can use array methods like `map()` or `reduce()` to create a new array and then assign it to the target object.
```javascript
var target = {};
Object.assign(target, arr.map(function (item) {
  return item;
}));
```
Keep in mind that these alternatives might be less efficient or more verbose than `Object.assign()` or the spread operator.

I hope this explanation helps you understand what's being tested and provides a solid foundation for exploring JavaScript performance optimization!

Related benchmarks:

object: assign vs spread (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):