Benchmark: Negation vs strict undefined

Script Preparation code:

var map = new Map();
map.set('x', 1);
map.set('y', 2);

Tests:

Negation
const z = map.get('z'); if (!z) { map.set('z', 3); }
Strict undefined
const z = map.get('z'); if (z === undefined) { map.set('z', 3); }
Strict void 0
const z = map.get('z'); if (z === void 0) { map.set('z', 3); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Negation
Strict undefined
Strict void 0

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/18.6 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
Negation	207358864.0 Ops/sec
Strict undefined	420803520.0 Ops/sec
Strict void 0	430807040.0 Ops/sec

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.

**What is tested?**

The provided JSON represents a benchmark test case that compares three different approaches to handling the absence of a key in a Map object. Specifically, it tests:

1. **Negation**: Using the logical NOT operator (`!`) to check if a value is undefined or null.
2. **Strict undefined**: Using the `undefined` keyword to check if a value is explicitly defined as such (i.e., not undefined).
3. **Strict void 0**: Using the `void 0` expression, which is equivalent to `undefined`, to check for undefined values.

**Options compared**

The benchmark compares these three approaches:

* **Negation**: This approach uses the logical NOT operator (`!`) to check if a value is undefined or null.
	+ Pros: Simple and concise, works in most cases.
	+ Cons: May not be as precise as other approaches, can lead to false positives (e.g., `null` values).
* **Strict undefined**: This approach uses the `undefined` keyword to check for explicitly defined values that are not undefined.
	+ Pros: More precise than negation, handles null values correctly.
	+ Cons: May be less concise and more verbose.
* **Strict void 0**: This approach uses the `void 0` expression (equivalent to `undefined`) to check for undefined values.
	+ Pros: Similar to strict undefined, but with a slightly different syntax.
	+ Cons: Same pros and cons as strict undefined.

**Other considerations**

In addition to these approaches, other factors may affect the performance of this benchmark, such as:

* The specific JavaScript engine or implementation being used (e.g., V8 in Chrome).
* The size and complexity of the Map object.
* The presence of other operations or overhead in the test code.

**Libraries and special JS features**

This benchmark does not use any external libraries. However, it does rely on the built-in `Map` object and its methods (e.g., `get()`, `set()`).

There are no special JavaScript features mentioned in the provided code snippets.

**Alternatives**

If you're looking for alternative approaches to handle undefined values in a Map object, you might consider:

* Using a third-party library like Lodash or Moment.js, which provide utility functions for handling null and undefined values.
* Implementing custom logic using techniques like coercion (e.g., `toString()` calls) or type checking.

Keep in mind that these alternatives may introduce additional overhead or dependencies, so it's essential to consider the specific requirements of your use case before choosing an approach.

Related benchmarks:

Negation vs strict undefined (version: 0)

Comparing performance of: Negation vs Strict undefined vs Strict void 0

Created: 4 years ago by: Guest

Jump to the latest result

Negation

Strict undefined

Strict void 0

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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