Benchmark: rest args vs no args

Script Preparation code:

let x = 0;
function testRestArgs(...args) {
  x++;
}

let y = 0;
function testNoArgs() {
  y++;
}

Tests:

rest args
testRestArgs('a', 1, 'b', 2, 'c', 3);
no args
testNoArgs('a', 1, 'b', 2, 'c', 3);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
rest args
no args

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/114.0.0.0 Safari/537.36 Edg/114.0.1823.51

Browser/OS: Chrome 114 on Windows

View result in a separate tab

Test name	Executions per second
rest args	11456816.0 Ops/sec
no args	12601550.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON data for the JavaScript microbenchmark, MeasureThat.net.

**Benchmark Definition**

The benchmark compares two approaches:

1. **Rest Args (`testRestArgs`)**: This function takes an arbitrary number of arguments using the rest parameter syntax (`...args`). The function increments a variable `x` for each argument passed.
2. **No Rest Args (`testNoArgs`)**: This function expects a specific number and sequence of arguments. It increments another variable `y` for each argument passed.

**Options Compared**

The benchmark compares these two approaches, which differ in how the function handles varying numbers of arguments.

**Pros and Cons**

* **Rest Args (Using Rest Parameters)**
	+ Pros:
		- Can handle a variable number of arguments, making it more flexible.
		- Reduces boilerplate code.
	+ Cons:
		- May lead to unexpected behavior if not used carefully.
		- Some older browsers or environments might not support rest parameters (although Chrome 114, as shown in the benchmark results, does).
* **No Rest Args (Using Fixed Argument List)**
	+ Pros:
		- Can be more predictable and controlled when handling a fixed number of arguments.
		- Often used for compatibility reasons with older browsers or environments.
	+ Cons:
		- Requires specifying the exact sequence and number of arguments, which can lead to less flexibility.

**Library Usage**

In this benchmark, no external libraries are explicitly mentioned. However, rest parameters were introduced in ECMAScript 2015 (ES6), which is supported by modern browsers like Chrome 114.

**Special JS Features/Syntax**

The benchmark uses rest parameters (`...args` and `...`) and function overloading/variadic functions (e.g., `testRestArgs('a', 1, 'b', 2, 'c', 3)`), which are features introduced in ECMAScript 2015. These features allow for more flexible function definitions.

**Alternatives**

If you need to compare or test other JavaScript approaches, consider the following alternatives:

* Using prototypes and object inheritance instead of functions.
* Implementing callback functions or promises for asynchronous programming.
* Testing different scope rules (e.g., `var`, `let`, `const`) or execution context differences between browsers.

For more specific testing requirements, you may also explore other benchmarks or tools designed for JavaScript performance comparison, such as:

* JSPerf
* Micro benchmarking libraries like Benchmark.js or Fast Bench

Related benchmarks:

rest args vs no args (version: 0)

Comparing performance of: rest args vs no args

Created: one year ago by: Guest

Jump to the latest result

rest args

no args

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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