Benchmark: double bang vs typeof check

Tests:

double bang
const obj = Object.assign( function() {}, { x: 1 }, ); for (let i = 0; i < 100000; i++) !!obj;
typeof
const obj = Object.assign( function() {}, { x: 1 }, ); for (let i = 0; i < 100000; i++) typeof obj === 'object' || typeof obj === 'function';

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
double bang
typeof

Fastest: N/A

Slowest: N/A

Latest run results:

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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 compares two approaches to test if an object is not null or undefined:

1. **Double Bang** (`!!obj`)
2. **typeof Check** (`typeof obj === 'object' || typeof obj === 'function'`)

These approaches are compared in two separate test cases, each with a different script preparation code.

**Script Preparation Code**

The script preparation code is used to set up the environment for the benchmark. In this case, it's simply an object creation using `Object.assign()`:
```javascript
const obj = Object.assign(
  function() {},
  { x: 1 }
);
```
This creates a new object with a single property `x` and assigns it to the `obj` variable.

**Double Bang (`!!obj`)**

The double bang operator (`!!`) is a JavaScript feature that converts its operand to a boolean value. When applied to an object, it returns `true` if the object has any properties (i.e., is not null or undefined).

**typeof Check (`typeof obj === 'object' || typeof obj === 'function'`)**

The `typeof` operator checks the type of its operand and returns one of several string values, such as `'object'`, `'function'`, etc. In this case, it's used to check if `obj` is either an object or a function.

**Pros and Cons**

1. **Double Bang (`!!obj`)**:
	* Pros: Simple, easy to read, and computationally efficient.
	* Cons: May not work as expected for complex objects with methods (see below).
2. **typeof Check (`typeof obj === 'object' || typeof obj === 'function'`)**:
	* Pros: More accurate and robust for complex objects, but slightly more computationally expensive.
	* Cons: Less straightforward to read and may require additional checks.

**Other Considerations**

When using the double bang operator, it's essential to note that it will return `true` if `obj` has any properties, including methods (e.g., functions). If you want to check only for objects without properties or methods, you may need to use a different approach.

**Library and Special JS Features**

There is no library mentioned in the benchmark definition. However, if you're interested in exploring more libraries or features, MeasureThat.net offers a wide range of benchmarks that cover various aspects of JavaScript performance.

If you'd like to explore other alternatives, here are a few options:

1. **Benchmarking libraries**: Libraries like WebPageTest, BrowserBench, and Benchmark.js provide more comprehensive benchmarking capabilities.
2. **Native JavaScript features**: You can also experiment with native JavaScript features like `atob()`, `btoa()`, or `JSON.parse()` to compare their performance.

Remember that the choice of approach depends on your specific use case, performance requirements, and personal preferences.

Related benchmarks:

double bang vs typeof check (version: 0)

Comparing performance of: double bang vs typeof

Created: 4 years ago by: Guest

Jump to the latest result

double bang

typeof

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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