Benchmark: Object.assign vs foreach set

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 };
foreach
var params = [ ["b", "hello"], ["c", true], ["a", 5] ]; var other = { a: 2 }; params.forEach(style => { other[style[0]] = style[1]; });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.assign
spread operator
foreach

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:134.0) Gecko/20100101 Firefox/134.0

Browser/OS: Firefox 134 on Windows

View result in a separate tab

Test name	Executions per second
Object.assign	14859739.0 Ops/sec
spread operator	9825907.0 Ops/sec
foreach	18765666.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

**Benchmark Overview**

The provided benchmark measures the performance of three different approaches to merge objects in JavaScript:

1. `Object.assign()`
2. Spread operator (`{ ... }`)
3. `forEach()` loop

**Options Compared**

Each test case compares two or more options, allowing users to see which approach is fastest.

**Pros and Cons of Each Approach**

* **`Object.assign()`**: This method is a built-in JavaScript function that takes an object and merges it with another object. It's concise but can be slow due to its overhead.
	+ Pros: Concise syntax, widely supported
	+ Cons: Can be slow, may not work as expected with certain data types
* **Spread Operator (`{ ... }`)**: This method uses the spread operator (`...`) to merge objects. It's more efficient than `Object.assign()` and can handle complex object structures.
	+ Pros: Efficient, flexible syntax, handles complex objects well
	+ Cons: May not be supported in older browsers or JavaScript versions
* **`forEach()` Loop**: This approach uses a loop to iterate over the properties of an array (or other iterable) and merges them into a new object. It's often slower than the spread operator but can be useful for more complex merge scenarios.
	+ Pros: Can handle complex objects, flexible syntax
	+ Cons: May be slow, less efficient than spread operator

**Library and Purpose**

There is no specific library mentioned in the benchmark definitions. The `Object.assign()` method is a built-in JavaScript function, while the spread operator (`{ ... }`) is also a native part of modern JavaScript.

**Special JS Features or Syntax**

The spread operator (`{ ... }`) uses a new syntax introduced in ECMAScript 2018 (ES10). This feature allows for more concise and expressive object merging. The `forEach()` loop uses a built-in JavaScript method, but it's not as elegant as the spread operator.

**Other Alternatives**

If you need to merge objects in JavaScript, there are other alternatives:

* Using `Object.assign()` with an array of key-value pairs (`Object.assign({}, ...props)`)
* Using a library like Lodash's `_.merge()` function
* Using a third-party library like Immutable.js for functional programming

Keep in mind that the choice of approach depends on your specific use case, performance requirements, and personal preference.

Related benchmarks:

Object.assign vs foreach set (version: 0)

Comparing performance of: Object.assign vs spread operator vs foreach

Created: 3 years ago by: Guest

Jump to the latest result

Object.assign

spread operator

foreach

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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