function h1(args) {
return args.map((x)=>x)
}
function h2(args) {
return args.map((x)=>x)
}
const els = h1(1);
const els = h1([1]);
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
rest arguments | |
array parameter |
Test name | Executions per second |
---|---|
rest arguments | 29817354.0 Ops/sec |
array parameter | 28900590.0 Ops/sec |
I'll break down the benchmark and explain what's being tested, compared, and their pros/cons.
Benchmark Definition:
The provided JSON defines a JavaScript microbenchmark named "rest parameters vs arguments 3". The script preparation code consists of two functions, h1
and h2
, which both use either rest parameters (...args
) or traditional function arguments (args
). The benchmark aims to compare the performance of these two approaches.
Options Compared:
The benchmark compares two options:
...args
): This syntax allows a function to accept an arbitrary number of arguments, which are collected into an array called args
.args
): In this approach, each argument is passed separately, and the function expects a specific number of arguments.Pros and Cons:
**Rest Parameters (...args
) Pros:
Cons:
undefined
is passed as the first argument)Traditional Function Arguments (`args``) Pros:
Cons:
Other Considerations:
The benchmark does not test any special JavaScript features or syntax, such as async/await, closures, or scope binding.
Library Usage:
There is no library usage in the provided code. The functions h1
and h2
are standalone definitions without referencing any external libraries.
Benchmark Preparation Code:
The script preparation code defines two functions, h1
and h2
, which both use either rest parameters or traditional function arguments to perform a simple mapping operation on an array of values. The purpose of these functions is to test the performance difference between rest parameters and traditional function arguments.
Individual Test Cases:
The benchmark consists of two individual test cases:
**: This test case calls
h1 with no arguments, which should be equivalent to calling it with an empty array (
[]`) in terms of performance.**: This test case passes a single-element array
[1]as the argument to
h1. The benchmark is interested in comparing this approach to passing separate values (
1`) as traditional function arguments.Latest Benchmark Result:
The latest benchmark result shows that both rest parameters and traditional function arguments perform similarly well, with Chrome 111 producing around 298 million executions per second for "rest arguments" and 289 million executions per second for "array parameter". This suggests that, in this specific test case, the performance difference between these two approaches is negligible.