var string = ' ';
var regPattern = new RegExp(/\A\s*\z/g);
regPattern.test(string)
string.trim().length === 0
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
regex | |
trim |
Test name | Executions per second |
---|---|
regex | 13625882.0 Ops/sec |
trim | 22432358.0 Ops/sec |
Let's break down the provided benchmark and explain what's being tested, compared, and their pros and cons.
Benchmark Overview
The benchmark is designed to compare the performance of two approaches: using regular expressions (regex) to test for whitespace characters versus using the trim()
method.
Script Preparation Code
The script preparation code defines a string variable string
containing only whitespace characters (" \t \t \t "
). It also creates a regex pattern regPattern
that matches one or more whitespace characters (/\\A\\s*\\z/g
) from the start (\\A
) to the end (\\z
) of the string.
Html Preparation Code
There is no HTML preparation code provided, which means that the benchmark only tests the JavaScript code.
Test Cases
The benchmark consists of two test cases:
regPattern.test(string)
expression, which attempts to match the regex pattern against the input string.string.trim().length === 0
, which removes all whitespace characters from the input string and checks if the resulting length is 0.Comparison
The benchmark compares the performance of these two approaches:
regex
test case)trim()
method to remove whitespace characters (trim
test case)Pros and Cons
Here's a brief analysis of each approach:
regex
test case)Pros:
Cons:
trim()
method due to the overhead of compiling and executing a regex pattern.trim
test case)Pros:
Cons:
Library Usage
The trim()
method uses the built-in JavaScript String.prototype.trim() method, which is implemented in V8 (the JavaScript engine used by Google Chrome).
Special JS Features/Syntax
There are no special features or syntax used in this benchmark that would require specific knowledge of JavaScript beyond what's discussed above.
Other Alternatives
If you wanted to compare the performance of different approaches to remove whitespace characters, other alternatives might include:
\s+
or [^\S]
, which may be more efficient than the trim()
method for certain use cases.Keep in mind that these alternatives would require additional code and analysis to determine their performance characteristics.