Benchmark: Performance of Object.keys(tree).map(Number) vs for...in

Script Preparation code:

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

Tests:

Object.keys(tree).map(Number)
Object.keys(a).map(Number)
for...in
const arr = []; for (let key in a) { arr.push(Number(a[key])); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.keys(tree).map(Number)
for...in

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.116 Safari/537.36

Browser/OS: Chrome 83 on Linux

View result in a separate tab

Test name	Executions per second
Object.keys(tree).map(Number)	950968.1 Ops/sec
for...in	480085.1 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and its test cases.

**Benchmark Overview**

The benchmark compares the performance of two approaches for iterating over an object's keys and converting their values to numbers:

1. `Object.keys(tree).map(Number)`
2. `for...in` loop with `Number(a[key])`

These approaches are being compared to determine which one is more efficient in terms of execution speed.

**Options Compared**

The benchmark compares two options:

* Using the `Object.keys()` method followed by the `map()` method to iterate over an object's keys and convert their values to numbers.
* Using a traditional `for...in` loop with `Number(a[key])` to achieve the same result.

**Pros and Cons of Each Approach**

1. **`Object.keys(tree).map(Number)`**
	* Pros:
		+ More concise and readable code
		+ Less prone to errors due to its declarative nature
	* Cons:
		+ May have slower execution speed due to the creation of an intermediate array
		+ Not suitable for large datasets due to memory constraints
2. **`for...in` loop**
	* Pros:
		+ More control over iteration and access to object properties
		+ Suitable for large datasets without significant performance impact
	* Cons:
		+ More verbose code that can be error-prone
		+ Less readable due to its procedural nature

**Library Used**

In the test cases, the `Object.keys()` method is used, which is a built-in JavaScript method that returns an array of a given object's property names. The purpose of this method is to provide a concise way to iterate over an object's keys without having to manually iterate using a loop.

**Special JS Feature/Syntax**

Neither of the test cases uses any special or advanced JavaScript features, making them accessible to a wide range of software engineers.

**Other Alternatives**

If you need to compare performance between different iteration approaches or optimize your code for performance, consider the following alternatives:

* Using `Array.prototype.forEach()` with an arrow function for more concise and readable code
* Utilizing modern JavaScript features like `for...of` loops for more efficient iteration over arrays and objects
* Employing micro-optimizations, such as using a `Set` to eliminate duplicate values or utilizing the `BigInt` data type for large numbers

Keep in mind that performance optimizations should always be driven by specific use cases and requirements.

Related benchmarks:

Performance of Object.keys(tree).map(Number) vs for...in (version: 0)

Comparing performance of: Object.keys(tree).map(Number) vs for...in

Created: 4 years ago by: Guest

Jump to the latest result

Object.keys(tree).map(Number)

for...in

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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