Benchmark: typeof vs cached typeof (3 scans)

Script Preparation code:

var obj = {};

Tests:

uncached typeof
for (let n = 0; n < 1000; n++) { if (typeof obj === 'object') { if (typeof obj === 'object') { if (typeof obj === 'object') { return true; } } } }
cached typeof
for (let n = 0; n < 1000; n++) { const isObject = typeof obj; if (isObject) { if (isObject) { if (typeof obj === 'object') { return true; } } } }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
uncached typeof
cached typeof

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) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.36

Browser/OS: Chrome 126 on Windows

View result in a separate tab

Test name	Executions per second
uncached typeof	9312596.0 Ops/sec
cached typeof	13586606.0 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 and understand what's being tested.

**Benchmark Overview**

The provided benchmark compares two approaches to check if an object is an instance of another object using the `typeof` operator: `uncached typeof` and `cached typeof`. The goal is to measure which approach is faster, as indicated by the "ExecutionsPerSecond" metric in the latest benchmark result.

**Options Compared**

The benchmark tests two options:

1. **Uncached typeof**: This approach uses a direct call to `typeof obj`, without any caching mechanism.
2. **Cached typeof**: This approach uses a cached result for the `typeof` operator, which is assumed to be stored in some hidden context (not explicitly shown in the benchmark).

**Pros and Cons**

* **Uncached typeof**:
	+ Pros: Simple and straightforward implementation.
	+ Cons: Each call to `typeof obj` performs an expensive operation, leading to slower performance.
* **Cached typeof**:
	+ Pros: Can potentially reduce the number of operations performed by caching the result.
	+ Cons: Requires additional setup and management of the cache, which can add complexity.

**Library Usage**

The benchmark uses a library called `typeof` (not explicitly mentioned in the JSON), which is assumed to provide an implementation for the `typeof` operator. The exact details of this library are not shown in the benchmark.

**Special JS Feature/Syntax**

There's no explicit mention of special JavaScript features or syntax being used in this benchmark. However, it's worth noting that the use of the `let` keyword with a block scope (in the `for` loop) is a modern JavaScript feature introduced in ECMAScript 2015.

**Alternatives**

Other approaches to check if an object is an instance of another object include:

1. **Using instanceof**: This method is more straightforward and efficient than using the `typeof` operator.
2. **Using a library like Lodash**: Lodash provides a function called `isPlainObject()` that can be used to check if an object is an instance of another object.

Here's an example implementation using `instanceof`:
```javascript
function isObject(other) {
  return obj instanceof other;
}
```
And here's an example implementation using Lodash:
```javascript
import _ from 'lodash';

function isObject(other) {
  return _.isPlainObject(obj);
}
```
These alternatives can be used as an additional benchmark to compare with the `typeof` operator approach.

Related benchmarks:

typeof vs cached typeof (3 scans) (version: 0)

Comparing performance of: uncached typeof vs cached typeof

Created: 3 years ago by: Guest

Jump to the latest result

uncached typeof

cached typeof

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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