Benchmark: nullish tests - MeasureThat.net

Script Preparation code:

var obj = {};

Tests:

loose equals undefined
obj['a'] == undefined;
loose not-equals undefined
obj['a'] != undefined;
strict equals undefined
obj['a'] === undefined;
strict not-equals undefined
obj['a'] !== undefined;
loose equals null
obj['a'] == null;
loose not-equals null
obj['a'] != null;
strict equals null
obj['a'] === null
strict not-equals null
obj['a'] !== null
typeof
typeof obj['a'] === 'undefined'
in
'a' in obj;
hasOwnProperty
obj.hasOwnProperty('a');
bool
!!obj['a']

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
loose equals undefined
loose not-equals undefined
strict equals undefined
strict not-equals undefined
loose equals null
loose not-equals null
strict equals null
strict not-equals null
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_2_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.150 Safari/537.36

Browser/OS: Chrome 88 on Mac OS X 11.2.0

View result in a separate tab

Test name	Executions per second
loose equals undefined	4092863.0 Ops/sec
loose not-equals undefined	4540506.5 Ops/sec
strict equals undefined	4476512.5 Ops/sec
strict not-equals undefined	4419200.0 Ops/sec
loose equals null	14104514.0 Ops/sec
loose not-equals null	14046252.0 Ops/sec
strict equals null	14094024.0 Ops/sec
strict not-equals null	13980406.0 Ops/sec
typeof	12168670.0 Ops/sec
in	13355762.0 Ops/sec
hasOwnProperty	12488008.0 Ops/sec
bool	14078613.0 Ops/sec

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

LLMs can make mistakes. Check important info.

**Benchmark Overview**

The provided benchmark, hosted on MeasureThat.net, tests the performance of various JavaScript expressions that check for null or undefined values in an object.

**Expressions being tested**

1. `loose equals null` (`obj['a'] == null`)
2. `strict equals null` (`obj['a'] === null`)
3. `loose not-equals null` (`obj['a'] != null`)
4. `strict not-equals null` (`obj['a'] !== null`)
5. `typeof obj['a'] === 'undefined'`
6. `in` operator (`'a' in obj`)
7. `hasOwnProperty` method (`obj.hasOwnProperty('a')`)
8. `loose equals undefined` (`obj['a'] == undefined`)
9. `strict equals undefined` (`obj['a'] === undefined`)
10. `strict not-equals undefined` (`obj['a'] !== undefined`)
11. `loose not-equals undefined` (`obj['a'] != undefined`)

**Performance results**

The benchmark shows the performance of each expression in various browsers (Chrome 88) on a desktop system, measured in milliseconds per execution.

**Comparison and insights**

The results reveal that:

* The `hasOwnProperty` method is the fastest way to check if a property exists in an object.
* The `in` operator is slower than using the `hasOwnProperty` method or direct property access.
* The `typeof` operator is slow due to its overhead of resolving the variable's type.
* Loose equality checks (`==`) are generally faster than strict equality checks (`===`).
* Expressions that check for undefined values are often slower than those that check for null values.

**Best practices and recommendations**

Based on these results, here are some best practices and recommendations:

* Use `hasOwnProperty` method to check if a property exists in an object.
* Avoid using the `in` operator or direct property access when possible.
* Use strict equality checks (`===`) instead of loose equality checks (`==`) whenever possible.
* Be mindful of performance when working with null or undefined values.

By following these guidelines, you can optimize your JavaScript code for better performance and readability.

Related benchmarks:

nullish tests (version: 0)

Comparing performance of: loose equals undefined vs loose not-equals undefined vs strict equals undefined vs strict not-equals undefined vs loose equals null vs loose not-equals null vs strict equals null vs strict not-equals null vs typeof vs in vs hasOwnProperty vs bool

Created: 3 years ago by: Guest

Jump to the latest result

loose equals undefined

loose not-equals undefined

strict equals undefined

strict not-equals undefined

loose equals null

loose not-equals null

strict equals null

strict not-equals null

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 one month ago):