Benchmark: Compare typeof vs null check

Script Preparation code:

const value = null

Tests:

Is number
const value = null return typeof value === 'number'
Is null
const value = null return value == null

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Is number
Is null

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/131.0.0.0 Safari/537.36

Browser/OS: Chrome 131 on Windows

View result in a separate tab

Test name	Executions per second
Is number	60732252.0 Ops/sec
Is null	40370204.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down what is being tested in the provided JSON data.

**Benchmark Definition**

The benchmark definition is comparing two approaches to check if a value is `null` or not:

1. Using `typeof` operator with `null`: `const value = null; return typeof value === 'number'`
2. Direct equality check using `==` operator: `const value = null; return value == null`

**Pros and Cons of Each Approach**

1. **Using `typeof` operator**:
	* Pros:
		+ More explicit and clear intention
		+ Less prone to errors due to type coercion
	* Cons:
		+ May be slower or more computationally expensive due to the extra operation
2. **Direct equality check using `==` operator**:
	* Pros:
		+ Typically faster or more efficient, as it's a direct comparison without additional operations
	* Cons:
		+ More prone to errors due to type coercion (e.g., comparing a number with a string)
		+ Less readable and maintainable due to the potential for subtle bugs

**Other Considerations**

Both approaches have their trade-offs. In general, `typeof` is considered more reliable and safer when working with values that may be unexpectedly coerced during comparisons.

**Library Usage**

There is no explicit library mentioned in the provided data. However, some libraries like `lodash` or `assert` might provide functions that could be used for these types of checks.

**Special JS Features/Syntax**

None are explicitly mentioned in this example.

**Other Alternatives**

For similar benchmarks, you might consider:

* Using `instanceof` operator to check if a value is an instance of `Number`
* Utilizing the `is-null` library (e.g., `npm install is-null`) for more explicit null checks
* Comparing the performance of other operators like `===` or `!=`

Related benchmarks:

Compare typeof vs null check (version: 0)

Comparing performance of: Is number vs Is null

Created: 4 years ago by: Guest

Jump to the latest result

Is number

Is null

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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