Benchmark: Spread vs Traditional

Script Preparation code:

var obj = { a: 'a', b: 'b' };

Tests:

Spread
const { a, b } = obj;
Traditional
var a = obj.a; var b = obj.b;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Spread
Traditional

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 6 years ago)

User agent: Mozilla/5.0 (Linux; Android 7.1.1; MI 6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.110 Mobile Safari/537.36

Browser/OS: Chrome Mobile 70 on Android 7.1.1

View result in a separate tab

Test name	Executions per second
Spread	4783256.5 Ops/sec
Traditional	2641296.5 Ops/sec

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

LLMs can make mistakes. Check important info.

I'd be happy to help explain the benchmark and its results.

**Benchmark Definition**

The benchmark measures the performance difference between two approaches: using the spread operator (`...`) to extract properties from an object, versus using traditional object property access (e.g., `obj.a`).

**Script Preparation Code**

The script preparation code defines a sample object `obj` with two properties: `a` and `b`, both initialized with string values.

**Html Preparation Code**

The html preparation code is empty, indicating that this benchmark does not rely on any specific HTML structure or rendering.

**Individual Test Cases**

There are two test cases:

1. **Spread**: This test case uses the spread operator to extract properties from the `obj` object and assigns them to separate variables `a` and `b`. The benchmark definition code is: `const { a, b } = obj;`
2. **Traditional**: This test case uses traditional object property access to extract properties from the `obj` object and assigns them to separate variables `a` and `b`. The benchmark definition code is: `var a = obj.a; var b = obj.b;`

**Pros and Cons of Each Approach**

* **Spread Operator (...)**:
	+ Pros:
		- More concise and readable syntax.
		- Can be more efficient, as it avoids the need for explicit variable declarations.
	+ Cons:
		- May not be supported by older browsers or environments that don't recognize the spread operator.
		- Can lead to slower performance in some cases (e.g., due to the creation of new objects).
* **Traditional Object Property Access**:
	+ Pros:
		- Widely supported across various browsers and environments.
		- Can be more predictable and easier to optimize, as the behavior is well-defined.
	+ Cons:
		- Less concise and readable syntax compared to the spread operator.

**Library and Purpose**

There are no libraries explicitly mentioned in this benchmark. However, it's worth noting that modern JavaScript engines (e.g., V8) have built-in optimizations for object property access, which can affect performance.

**Special JS Features or Syntax**

The benchmark uses the **spread operator**, a feature introduced in ECMAScript 2015 (ES6). The spread operator allows you to extract properties from an object and assign them to separate variables in a more concise syntax. While not all browsers support ES6 features, most modern browsers (including Chrome Mobile) do.

**Other Alternatives**

In case the spread operator is not supported or preferred for performance reasons, alternative approaches could be:

1. Using `Object.assign()` to extract properties from an object.
2. Using a library like Lodash's `pick` function to extract specific properties from an object.

However, these alternatives may add extra overhead and are generally less concise than the spread operator approach.

Related benchmarks:

Spread vs Traditional (version: 0)

Comparing performance of: Spread vs Traditional

Created: 6 years ago by: Guest

Jump to the latest result

Spread

Traditional

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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