var reConstructor = new RegExp('^[0-9a-fA-F]{24}$')
var reSimpleConstructor = RegExp('^[0-9a-fA-F]{24}$')
var reLiteral = /^[0-9a-fA-F]{24}$/
reConstructor.test('132abc67219f019afe12901a')
reSimpleConstructor.test('132abc67219f019afe12901a')
reLiteral.test('132abc67219f019afe12901a')
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
new Regex | |
Regex | |
Literal |
Test name | Executions per second |
---|---|
new Regex | 6069228.5 Ops/sec |
Regex | 6228227.5 Ops/sec |
Literal | 6129453.0 Ops/sec |
I'll break down the benchmark for you.
Overview
The provided benchmark tests three ways of creating regular expressions in JavaScript: using RegExp
constructor, a literal syntax, and a shorthand syntax (new RegExp
). The test cases measure the performance difference between these approaches.
Benchmark Definition JSON
The benchmark definition JSON contains two parts:
reConstructor
: Creates a new regular expression object using the RegExp
constructor.reSimpleConstructor
: Creates a shorthand regular expression object, equivalent to new RegExp
.reLiteral
: Defines a literal regular expression pattern, which is used directly in the test cases.Individual Test Cases
The benchmark defines three individual test cases:
reConstructor.test('132abc67219f019afe12901a')
: Tests the performance of creating a regular expression using the RegExp
constructor.reSimpleConstructor.test('132abc67219f019afe12901a')
: Tests the performance of shorthand syntax (new RegExp
).reLiteral.test('132abc67219f019afe12901a')
: Tests the performance of literal syntax.Performance Comparison
The benchmark measures the execution frequency (in executions per second) for each test case, which represents the performance difference between the three approaches:
Regex
(using new RegExp
) has a slightly higher execution frequency compared to Literal
.Literal
is the fastest approach.new Regex
has a lower execution frequency compared to Regex
.Pros and Cons of Each Approach
RegExp
constructor: This approach provides more control over the regular expression's flags, options, and behavior. However, it may lead to slightly slower performance due to the overhead of creating an object.new RegExp
): This approach is concise and often used in practice, but it may have less control over the regular expression's behavior compared to the RegExp
constructor.Library and Special Features
In this benchmark, there are no external libraries used. Additionally, there are no special JavaScript features (e.g., async/await
, promises
) mentioned in the code snippets.
Other Alternatives
If you need to compare performance of different regular expression engines or syntaxes, here are some alternatives:
javascript-regexpr
: A benchmarking library specifically designed for comparing performance between different regular expression implementations.regex-benchmark
: Another benchmarking tool that allows comparing performance between various regular expression engines and syntaxes.