Benchmark: isNullish variants 2

Script Preparation code:

var arr = [];
var i = 0;

while (i <= 1E5) arr[i] = i++;

Tests:

nullish coalescing
const isNullish = (value) => (value ?? true) === true ? true : false; arr.forEach(i => isNullish(i));
classic
const isNullish = value => value === null || value === undefined; arr.forEach(i => isNullish(i));
classic with ==
const isNullish = value => value == null; arr.forEach(i => isNullish(i));

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
nullish coalescing
classic
classic with ==

Fastest: N/A

Slowest: N/A

Latest run results:

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

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark and explain what's being tested, compared, and other considerations.

**Benchmark Definition**

The benchmark is testing three variants of checking for nullish values (i.e., values that can be null or undefined) in an array `arr`. The nullish variants are:

1.  "nullish coalescing"
2.  "classic"
3.  "classic with =="

**Nullish Coalescing**

The first variant, "nullish coalescing," uses the optional chaining operator (`?.`) and the fact that a null or undefined value will result in a falsy value. The test case is:

```javascript
const isNullish = (value) => (value ?? true) === true ? true : false;
arr.forEach(i => isNullish(i));
```

This approach takes advantage of the fact that a null or undefined value will be coerced to `false` in a boolean context. The `(value ?? true)` part checks if the value is nullish, and if so, returns `true`. If not, it returns `false`.

Pros: This approach is concise and leverages the optional chaining operator.

Cons: The performance might be affected by the overhead of the optional chaining operator.

**Classic**

The second variant, "classic," uses a simple check for null or undefined values:

```javascript
const isNullish = value => value === null || value === undefined;
arr.forEach(i => isNullish(i));
```

This approach directly checks if the value is `null` or `undefined`, and returns `true` if so.

Pros: This approach is straightforward and easy to understand.

Cons: This approach might be slower due to the direct comparison.

**Classic with ==**

The third variant, "classic with ==," uses a similar approach as the classic variant but adds an extra step by using the `==` operator:

```javascript
const isNullish = value => value == null;
arr.forEach(i => isNullish(i));
```

This approach also checks if the value is `null`, but uses the `==` operator to do so.

Pros: This approach might be slightly faster than the classic variant due to the optimized implementation of the `==` operator.

Cons: This approach adds unnecessary overhead due to the `==` operator.

**Library and Special JS Features**

None of the test cases use a specific library or special JavaScript features other than the optional chaining operator (`?.`).

**Other Considerations**

When comparing these variants, it's essential to consider the following factors:

*   Performance: How quickly does each variant execute?
*   Readability: Which variant is more readable and easier to understand?
*   Maintenance: How easy is it to maintain or modify each variant?

In this case, the nullish coalescing approach might be a good compromise between performance and readability.

**Alternatives**

If you're looking for alternatives to these variants, consider the following:

1.  **Using `typeof`**: Instead of checking if a value is `null` or `undefined`, you can use the `typeof` operator to check its type.
    ```javascript
const isNullish = value => typeof value !== 'object';
arr.forEach(i => isNullish(i));
```
2.  **Using a custom function**: You can create a custom function that checks if a value is nullish and returns a boolean result.
    ```javascript
const isNullish = (value) => value === null || value === undefined;
arr.forEach(i => isNullish(i));
```

However, the provided variants are already quite concise and efficient, so it might not be necessary to explore alternative approaches.

Related benchmarks:

isNullish variants 2 (version: 0)

Comparing performance of: nullish coalescing vs classic vs classic with ==

Created: 4 years ago by: Guest

Jump to the latest result

nullish coalescing

classic

classic with ==

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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