Benchmark: JS presence - MeasureThat.net

Script Preparation code:

var obj = { a: 1, b: 2, c: 3, d: 4, e: 5 };

Tests:

undefined
undefined !== obj.d;
typeof
'undefined' !== typeof obj.d;
in
'd' in obj;
hasOwnProperty
obj.hasOwnProperty( 'd' );
bool
!! obj.d;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
undefined
typeof
in
hasOwnProperty
bool

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 11_1_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.182 Safari/537.36

Browser/OS: Chrome 88 on Mac OS X 11.1.0

View result in a separate tab

Test name	Executions per second
undefined	5214269.5 Ops/sec
typeof	17295586.0 Ops/sec
in	16955730.0 Ops/sec
hasOwnProperty	15751977.0 Ops/sec
bool	17459316.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks!

The provided JSON represents a benchmark test case for measuring object lookup performance in JavaScript. Specifically, it tests the performance of comparing an object property with different syntaxes and operators.

**Benchmark Definition**

The `Script Preparation Code` section defines a simple JavaScript object `obj` with five properties: `a`, `b`, `c`, `d`, and `e`. Each test case uses this object to perform a specific comparison.

Here are the six test cases:

1. `undefined !== obj.d;`: Tests comparing `undefined` with the value of `obj.d`.
2. `'undefined' !== typeof obj.d;`: Tests comparing a string literal `'undefined'` with the type of `obj.d` using the `typeof` operator.
3. `'d' in obj;`: Tests checking if the property 'd' exists in the object `obj` using the `in` operator.
4. `obj.hasOwnProperty('d');`: Tests checking if the property 'd' is a direct property of `obj`, not inherited from its prototype, using the `hasOwnProperty` method.
5. `!! obj.d;`: Tests converting the value of `obj.d` to a boolean value using the logical NOT operator `!!`.
6. (This test case is skipped in the provided benchmark results) ...

Related benchmarks:

JS presence (version: 0)

Object lookup performance

Comparing performance of: undefined vs typeof vs in vs hasOwnProperty vs bool

Created: 3 years ago by: Guest

Jump to the latest result

undefined

typeof

in

hasOwnProperty

bool

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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