Benchmark: default parameters vs nullish coalesce

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

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	1559.0 Ops/sec
nullish coalesce	1620.5 Ops/sec

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

LLMs can make mistakes. Check important info.

The benchmark provided compares two different approaches for handling function parameters in JavaScript: using default parameters versus using the nullish coalescing assignment (??=) operator.

### Overview of Approaches:

1. **Default Parameters:**
   - In the function `one(param = 100)`, `param` uses a default value of `100` if no argument is provided when the function is called. This means that if an argument is passed that is `undefined` (or not passed at all), the default value will be used.
   - Pros:
     - Simplicity: The syntax is straightforward and easily understandable.
     - Clear intent: It is evident from the function signature what the default value is.
   - Cons:
     - If a value of `0` or `false` is passed explicitly, it will override the default value, leading to potentially unexpected results depending on context.

2. **Nullish Coalescing Assignment (??=):**
   - In the second function `two(param){param ??= 100; return param + 300}`, the `??=` operator checks if `param` is `null` or `undefined` before assigning it the value of `100`. This means that if `param` is explicitly set to other falsy values like `0`, `false`, or `''`, it will not use the default.
   - Pros:
     - More control: This method allows the function to accept other falsy values without overriding them with the default.
     - Enhanced flexibility: It is useful when the intention is to maintain any intended falsy values while still providing a default if the argument is not set.
   - Cons:
     - Slightly more complex syntax and could require additional understanding of the nullish coalescing behavior for some developers.

### Benchmark Results:

The benchmark tested both approaches with the same loop structure: `for(let i = 3000; --i;)`.

- **Nullish Coalescing:** Achieved an execution rate of approximately **1620.52 operations per second**.
- **Default Argument:** Achieved an execution rate of approximately **1559.05 operations per second**.

From these results, we see that the nullish coalescing approach performed slightly better. However, the difference in performance may not be significant enough for most use cases to dictate which approach should be utilized universally.

### Other Considerations:

- **Browser Compatibility:** The nullish coalescing assignment operator (??=) is supported in modern JavaScript environments (ES2021 and later). It's important to ensure that targeting environments support these features, especially when developing for older browsers or systems.
  
- **Maintenance and Readability:** Although performance is one consideration, code maintainability and readability are critical. Choosing a clearer syntax for team projects, where multiple developers may not have in-depth knowledge of advanced features, is often more beneficial.

### Alternatives:

- **Using Simple Conditional Statements:** Aside from using default parameters or nullish coalescing, simple conditional checks (e.g., `if (param === undefined) param = 100;`) can be used. This is explicit but may lead to more verbose code.
  
- **Object Destructuring:** If a function receives an object as input, default values can also be set within the destructuring of the object parameters themselves.

In summary, the benchmark compares the efficiency of handling function parameters through two modern JavaScript approaches and identifies the trade-offs associated with each, allowing developers to make informed decisions based on performance and the context of their application's requirements.

Related benchmarks:

default parameters vs nullish coalesce (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):