Benchmark: accessing null vs undefined

Tests:

null
for (let i = 0; i < 1000; i++) { null; }
undefined
for (let i = 0; i < 1000; i++) { undefined; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
null
undefined

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 9 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.1 Safari/605.1.15

Browser/OS: Safari 18 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
null	3220273.5 Ops/sec
undefined	3232010.5 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark and explain what's being tested.

**Benchmark Definition**

The benchmark is testing two different approaches to handling `null` and `undefined` values in JavaScript.

**Options Compared**

There are only two options being compared:

1. Accessing `null` using the `null` keyword.
2. Accessing `undefined` using the `undefined` keyword.

**Pros and Cons of Each Approach**

Both approaches have their advantages and disadvantages:

* **Accessing `null`**: When you access a variable that's explicitly set to `null`, it means you're checking for `null` and if it's present, you can take specific action. However, in modern JavaScript, this is not necessary because `null` is treated as `false` in most contexts (e.g., `if (var === null)`).
* **Accessing `undefined`**: When you access a variable that hasn't been initialized or has been deleted, it means you're checking for the absence of value. In modern JavaScript, this is essential because `undefined` is treated as a distinct value from other types, and attempting to use an uninitialized variable can lead to errors.

**Other Considerations**

In general, accessing `null` is generally considered bad practice because it's unnecessary and can lead to confusing code. Accessing `undefined`, on the other hand, is crucial for handling situations where variables are not initialized or have been deleted.

**Library/Dependency**

There is no library or dependency mentioned in this benchmark definition. The test cases rely solely on vanilla JavaScript.

**Special JS Feature/Syntax**

This benchmark does not use any special JavaScript features or syntax beyond basic variable assignment and conditional statements (e.g., `if` statements).

**Alternative Benchmarks**

To measure the performance of accessing `null` and `undefined`, other alternatives could include:

1. Benchmarking the execution time of a script that accesses an uninitialized variable versus one that uses the `undefined` keyword.
2. Comparing the execution time of accessing a variable that's explicitly set to `null` versus using a conditional statement to check for `null`.
3. Using a library like Jest or Mocha to write unit tests that measure the performance of different approaches to handling `null` and `undefined`.

In summary, this benchmark is measuring the performance difference between two basic JavaScript approaches to handling `null` and `undefined`. While both are valid, accessing `undefined` is generally considered more important due to its critical role in handling uninitialized variables.

Related benchmarks:

accessing null vs undefined (version: 0)

measurethat.net is weird

Comparing performance of: null vs undefined

Created: 4 years ago by: Guest

Jump to the latest result

null

undefined

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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