Benchmark: Object.assign 2 - MeasureThat.net

Script Preparation code:

var test = { 'a':1, 'b':2, 'c':3 };

Tests:

Regular assign
test['a'] = 4; test['d'] = 5; test['e'] = 6;
Object.assign
Object.assign(test, { 'a': 4 }); Object.assign(test, { 'd': 5 }); Object.assign(test, { 'e': 6 });
Object.assign multiple
Object.assign(test, { 'a': 4, 'd': 5, 'e':6 });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Regular assign
Object.assign
Object.assign multiple

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 break down the benchmark test and its components.

**Benchmark Definition JSON**

The provided JSON defines a benchmark named "Object.assign 2". This benchmark is used to compare the performance of different ways to assign values to an object in JavaScript.

**Script Preparation Code**

The script preparation code defines a test object `test` with three properties: `'a'`, `'b'`, and `'c'`. The value of property `'b'` is set to 2, while the values of properties `'a'` and `'c'` are set to 1 and 3, respectively.

**Html Preparation Code**

There is no HTML preparation code provided for this benchmark. This means that the benchmark only tests the JavaScript engine's performance without considering any GUI-related overhead or rendering tasks.

**Individual Test Cases**

The benchmark defines three test cases:

1. **Regular assign**: This test case assigns a new value to an existing property of the `test` object using simple assignment syntax (`test['a'] = 4;`). Then, it tries to assign values to non-existent properties `'d'` and `'e'`.
2. **Object.assign**: This test case uses the `Object.assign()` method to assign values to the `test` object. It calls `Object.assign()` three times with different objects containing new values for each property.
3. **Object.assign multiple**: This test case is similar to the previous one but assigns all properties in a single call using `Object.assign()`. The last assignment overwrites any existing values.

**Library and Special JS Features**

There are no libraries or special JavaScript features mentioned in the benchmark definition. However, it's worth noting that `Object.assign()` was introduced as a standard method in ECMAScript 2015 (ES6), so this benchmark may be testing the performance of older browsers that don't support this method.

**Comparison and Pros/Cons**

The benchmark compares three approaches:

1. **Regular assign**: This approach uses simple assignment syntax, which is straightforward but may incur additional overhead due to property lookups.
2. **Object.assign()**: This approach uses the `Object.assign()` method, which can be faster than regular assign because it avoids property lookups and can take advantage of native optimizations.
3. **Object.assign multiple**: This approach assigns all properties in a single call using `Object.assign()`, which may incur additional overhead due to object creation and merging.

The pros and cons of each approach are:

* Regular assign:
	+ Pros: Simple to implement, doesn't require any library or special features.
	+ Cons: May incur additional overhead due to property lookups.
* Object.assign():
	+ Pros: Faster than regular assign, can take advantage of native optimizations.
	+ Cons: Requires support for `Object.assign()` and may not be compatible with older browsers.
* Object.assign multiple:
	+ Pros: Assigns all properties in a single call, which might improve performance due to reduced overhead.
	+ Cons: May incur additional overhead due to object creation and merging.

**Other Alternatives**

If you wanted to test similar benchmarks, you could consider the following alternatives:

1. **Property access**: Test property access using bracket notation (`test['a'] = 4;`) or dot notation (`test.a = 4;`).
2. **Array assignment**: Test array assignment using `test.push()` or `test[0] = 4;`.
3. **Prototype chain lookup**: Test prototype chain lookup by adding a new property to the global object and then trying to access it on an instance of the object.
4. **Object creation**: Test object creation using the `new` keyword and various constructors (e.g., `Array`, `Object`, `Function`).

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:62.0) Gecko/20100101 Firefox/62.0

Browser/OS: Firefox 62 on Windows

View result in a separate tab

Test name	Executions per second
Regular assign	103014584.0 Ops/sec
Object.assign	3303982.2 Ops/sec
Object.assign multiple	5397635.5 Ops/sec

Related benchmarks:

Object.assign 2 (version: 0)

Test Object assign performance

Comparing performance of: Regular assign vs Object.assign vs Object.assign multiple

Created: 6 years ago by: Guest

Jump to the latest result

Regular assign

Object.assign

Object.assign multiple

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):