var k = new Array(10000);
k.fill(undefined);
k.fill(void 0);
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
undefined | |
void 0 |
Test name | Executions per second |
---|---|
undefined | 96315.2 Ops/sec |
void 0 | 94252.7 Ops/sec |
I'll break down the provided benchmark definition and test cases to explain what's being tested, compared, and their pros and cons.
Benchmark Definition The benchmark definition is a JSON object that contains information about the test case. Here's a breakdown of its components:
k
with 10,000 elements and assigns a value to it using new Array(10000);
. However, there's no JavaScript assignment operator (=
) in the code, which is unusual for benchmarking purposes.Test Cases The benchmark definition contains two individual test cases:
k.fill(undefined);
k
with the value undefined
.k.fill(void 0);
k
with the value 0
.Comparison
The two test cases are comparing the performance difference between using undefined
and void 0
when filling an array.
Pros and Cons
undefined
:undefined
is not a valid argument for fill()
(it's only supported in ECMAScript 5 and later).void 0
:void
keyword followed by 0
.void
operator.Other Considerations
new Array(10000);
in the script preparation code is unusual and might not be relevant to the benchmarking of fill()
.undefined
or void 0
should have any significant performance difference, as both values are essentially "no value" when used with fill()
.Library
There doesn't seem to be a specific library being used in these benchmark test cases. The code is standard JavaScript, and the only external resource mentioned is the browser's user agent string (RawUAString
) in the benchmark result.
Special JS Features or Syntax None of the provided code snippet uses any special JavaScript features or syntax that would require additional explanation.