const str = "https://firebasestorage.googleapis.com/v0/b/a-sketch-a-day-207420.appspot.com/o/things.jpg?alt=media&token=alan"
str.replace(
"https://firebasestorage.googleapis.com/v0/b/a-sketch-a-day-207420.appspot.com/o/",
"https://images.sketchaday.app/",
)
.replace(/\?.*/, "")
const str = "https://firebasestorage.googleapis.com/v0/b/a-sketch-a-day-207420.appspot.com/o/things.jpg?alt=media&token=alan"
str.replace(/https:\/\/firebasestorage.googleapis.com\/v0\/b\/a-sketch-a-day-207420.appspot.com\/o\/(.*)\?.*/, "https://images.sketchaday.app/$1")
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
twostep | |
regex |
Test name | Executions per second |
---|---|
twostep | 1627245.2 Ops/sec |
regex | 1394658.9 Ops/sec |
Let's break down the provided benchmark and explain what is tested, the different approaches compared, their pros and cons, and other considerations.
Benchmark Overview
The MeasureThat.net website allows users to create and run JavaScript microbenchmarks. The benchmark in question measures the performance difference between two approaches for replacing a specific string pattern in a URL: using str.replace()
with multiple arguments versus using regular expressions (regex) with a single regex pattern.
Script Preparation Code
Since there is no script preparation code provided, we'll focus on the individual test cases.
Individual Test Cases
There are only two test cases:
str.replace()
with multiple arguments:str.replace(
"https://firebasestorage.googleapis.com/v0/b/a-sketch-a-day-207420.appspot.com/o/",
"https://images.sketchaday.app/"
)
This approach replaces the first occurrence of "https://firebasestorage.googleapis.com/v0/b/a-sketch-a-day-207420.appspot.com/o/"
with "https://images.sketchaday.app/"
, and then replaces any remaining occurrences using the next argument.
str.replace(/https:\\/\\/firebasestorage.googleapis.com\\/v0\\/b\\/a-sketch-a-day-207420.appspot.com\\/o\\/(.*)\\?.*/, "https://images.sketchaday.app/$1")
This approach uses a regular expression to match the URL pattern and replace it with the new string.
Library and Purpose
In both test cases, the replace()
method is used. The str.replace()
method in JavaScript is a built-in method that replaces occurrences of a specified value in a string. In this benchmark, it's used to perform the replacement operations.
Special JS Features or Syntax
There are no special JS features or syntax mentioned in either test case.
Pros and Cons of Different Approaches
Here's a brief summary:
str.replace()
with multiple arguments:str.replace()
approach for complex patternsOther Considerations
When choosing between these approaches, consider the following:
str.replace()
might be a better choice.Alternatives
Some alternative approaches for replacing strings in JavaScript include:
lodash
or underscore
, which offer optimized string replacement functionsjs-stringify
or string-join
String.prototype.replace()
methodKeep in mind that the performance difference between these approaches may not be significant for simple use cases, but can make a noticeable impact when dealing with large datasets or complex replacements.