var dateTimeISO = '2024-08-21T17:00:00.000Z'var dateOnlyISO = '2024-08-21'var normalizeToLocalDate = (date) => ` ${date}`new Date(dateTimeISO)new Date(normalizeToLocalDate(dateTimeISO))new Date(dateOnlyISO)new Date(normalizeToLocalDate(dateOnlyISO))--enable-precise-memory-info flag.
| Test case name | Result |
|---|---|
| new Date(dateTimeISO) | |
| new Date(normalizeToLocalDate(dateTimeISO)) | |
| new Date(dateOnlyISO) | |
| new Date(normalizeToLocalDate(dateOnlyISO)) |
| Test name | Executions per second |
|---|---|
| new Date(dateTimeISO) | 4279278.5 Ops/sec |
| new Date(normalizeToLocalDate(dateTimeISO)) | 4273234.0 Ops/sec |
| new Date(dateOnlyISO) | 5783702.5 Ops/sec |
| new Date(normalizeToLocalDate(dateOnlyISO)) | 2984259.8 Ops/sec |
Let's dive into the world of JavaScript microbenchmarks!
Benchmark Definition
The provided JSON defines two benchmark definitions:
new Date(date) vs new Date(normalizeToLocalDate(date)) 2: This benchmark compares the performance of two approaches to create a Date object from a string:new Date(date)new Date(normalizeToLocalDate(date))Script Preparation Code
The script preparation code is provided in the "Script Preparation Code" field of the benchmark definition:
var dateTimeISO = '2024-08-21T17:00:00.000Z'
var dateOnlyISO = '2024-08-21'
var normalizeToLocalDate = (date) => ` ${date}`
This code defines two variables: dateTimeISO and dateOnlyISO. The normalizeToLocalDate function is also defined, which takes a date string as input and returns a modified version of it.
Html Preparation Code
The html preparation code is not provided in the benchmark definition. However, you can assume that it would be used to set up any necessary HTML environment for running the benchmarks.
Individual Test Cases
The individual test cases are defined in the "Test Name" field of each object:
[
{
"Benchmark Definition": "new Date(dateTimeISO)",
"Test Name": "new Date(dateTimeISO)"
},
{
"Benchmark Definition": "new Date(normalizeToLocalDate(dateTimeISO))",
"Test Name": "new Date(normalizeToLocalDate(dateTimeISO))"
},
{
"Benchmark Definition": "new Date(dateOnlyISO)",
"Test Name": "new Date(dateOnlyISO)"
},
{
"Benchmark Definition": "new Date(normalizeToLocalDate(dateOnlyISO))",
"Test Name": "new Date(normalizeToLocalDate(dateOnlyISO))"
}
]
These test cases create four different Date objects using the new Date() constructor, with varying inputs.
Library
There is no explicit library mentioned in the benchmark definition. However, the normalizeToLocalDate function uses template literals (introduced in ECMAScript 2015) to concatenate strings with the input date string. Template literals are a feature of JavaScript that allow you to embed expressions inside string literals.
Special JS Feature or Syntax
There is no special JavaScript feature or syntax mentioned in the benchmark definition. The only feature used is template literals (introduced in ECMAScript 2015), which is a built-in feature of modern JavaScript.
Other Alternatives
To run these benchmarks, you would need to create a web page that includes the HTML and script preparation code provided in the benchmark definition. You can then use a JavaScript execution engine or a benchmarking library (such as Benchmark.js) to execute the test cases and measure their performance.
Here's an example of how you could set up a basic environment for running these benchmarks:
<!DOCTYPE html>
<html>
<head>
<title>Benchmark</title>
</head>
<body>
<script src="benchmark.js"></script>
<script>
var dateTimeISO = '2024-08-21T17:00:00.000Z'
var dateOnlyISO = '2024-08-21'
var normalizeToLocalDate = (date) => ` ${date}`
function runBenchmark(benchmarkDefinition) {
var testCode = eval(benchmarkDefinition.BenchmarkDefinition)
// Execute the test code and measure its performance
console.log(testCode())
}
for (var i = 0; i < benchmarkTestCases.length; i++) {
runBenchmark(benchmarkTestCases[i])
}
</script>
</body>
</html>
Note that this is just a basic example, and you would need to modify it to suit your specific needs.
In conclusion, the provided benchmark definition uses modern JavaScript features such as template literals to create Date objects. The benchmarks compare the performance of two approaches: using new Date() directly versus using new Date(normalizeToLocalDate(date)).
