Benchmark: default parameters vs nullish coalesce 2

Script Preparation code:

function one(param = 100){return param + 300}
function two(param){param??=100;return param + 300}

Tests:

default
for(let i = 3000; --i;)one(null)
nullish coalesce
for(let i = 3000; --i;)two(null)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
default
nullish coalesce

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36

Browser/OS: Chrome 128 on Linux

View result in a separate tab

Test name	Executions per second
default	1556.6 Ops/sec
nullish coalesce	1600.0 Ops/sec

Autogenerated LLM Summary (model gpt-4o-mini, generated one year ago):

LLMs can make mistakes. Check important info.

The benchmark in question is designed to compare two different approaches for handling default parameters in JavaScript functions, specifically focusing on a situation where the input parameter might be `null`.

### Benchmark Overview

1. **Functions Tested:**
   - **`one(param = 100)`**: This function uses a default parameter mechanism. If no argument is provided when calling the function, or if `undefined` is passed (but not `null`), it will default `param` to `100`.
   - **`two(param)`**: This function employs the nullish coalescing assignment operator (`??=`). Here, if `param` is `null` or `undefined`, it assigns `100` to `param`, thereby allowing `param` to take a value of `null` without defaulting to `100`.

2. **Test Cases:**
   - The two benchmark test cases execute each function in a loop 3000 times, passing `null` as the argument:
     - **Default Parameters**: `one(null)`
     - **Nullish Coalescing**: `two(null)`

### Comparison of Approaches

#### 1. **Default Parameters**
   - **Pros**:
     - Simple and intuitive syntax.
     - Handles cases where no argument is passed (including `undefined`), defaulting to the specified value.
   - **Cons**:
     - If `null` is explicitly passed, `param` will be set to `null`, leading to potential unintended behavior depending on the function's logic.
     - Does not work well when distinguishing between "no value" and "explicitly set to `null`".

#### 2. **Nullish Coalescing Assignment (`??=`)**
   - **Pros**:
     - Explicitly tight control over defaults. It allows a developer to differentiate between `undefined` or `null` and actual values (e.g., `0` or `''`).
     - It preserves user input when `null` is a valid case.
   - **Cons**:
     - Relatively newer syntax (introduced in ECMAScript 2021), so may not be supported in older JavaScript environments.
     - Slightly more verboseness compared to default parameters.

### Benchmark Results

The results indicate that:
- The nullish coalescing approach (`two(null)`) achieved **1600.04 executions per second.**
- The default parameter approach (`one(null)`) achieved **1556.64 executions per second.**

This shows that the nullish coalescing operation might be slightly more performant than the traditional default parameter setting in this specific scenario.

### Other Considerations and Alternatives

- **Other Alternatives**:
  - Using `if` statements or ternary operators for handling defaults is another common approach that can yield different performance impacts based on the function complexity and the number of checks.
  - Another alternative is using the logical OR operator (`||`), but this can lead to unexpected behavior since it treats "falsy" values (like `0`, `false`, or `''`) the same as `null` or `undefined`.

By evaluating the methods in this benchmark, developers can make informed choices about which parameter handling approaches to use based on their needs related to performance, code clarity, and the specific requirements of the data they are working with.

Related benchmarks:

default parameters vs nullish coalesce 2 (version: 1)

Comparing performance of: default vs nullish coalesce

Created: one year ago by: Guest

Jump to the latest result

default

nullish coalesce

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gpt-4o-mini, generated one year ago):