const str = "https://firebasestorage.googleapis.com/v0/b/a-sketch-a-day-207420.appspot.com/o/"
str.includes("firebasestorage")
const str = "https://firebasestorage.googleapis.com/v0/b/a-sketch-a-day-207420.appspot.com/o/"
str.startsWith("https://fire")
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
includes | |
startsWith |
Test name | Executions per second |
---|---|
includes | 17921228.0 Ops/sec |
startsWith | 27554920.0 Ops/sec |
Let's break down the provided benchmark and its test cases.
Benchmark Overview
MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks. The provided benchmark definition consists of two individual test cases: startsWith
and includes
. These test cases compare the performance of two different string comparison methods in JavaScript.
Options Compared
The two options being compared are:
str.startsWith("https://fire/")
: This method checks if the string str
starts with the specified substring "https://fire/"
.str.includes("firebasestorage")
: This method checks if the string str
includes the specified substring "firebasestorage"
.Pros and Cons of Each Approach
startsWith
:includes
:startsWith
when searching for a specific prefix.Library Used
None of the provided test cases use any external libraries.
Special JS Feature/Syntax
The benchmark uses two standard JavaScript methods:
includes()
: Introduced in ECMAScript 2015 (ES6), this method is part of the standard library and provides a simple way to check if a string includes a specified substring.startsWith()
: Also introduced in ES6, this method is similar to includes()
, but checks for a more specific prefix.Other Alternatives
In JavaScript, other methods that could be used for string comparison include:
indexOf()
: Returns the index of the first occurrence of the specified substring. If not found, returns -1.localeCompare()
: Compares two strings using the current locale's rules and options.However, includes()
and startsWith()
are generally preferred over these alternatives due to their simplicity and efficiency.
Benchmark Preparation Code
The provided benchmark preparation code is empty, which means that the script being tested is already prepared by the user. In a real-world scenario, this code might include some setup or initialization steps to ensure consistent results across different browsers and environments.