const str = "utm_source"
str.startsWith("utm_")
const str = "utm_source"
str.includes("utm_")
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
startsWith | |
includes |
Test name | Executions per second |
---|---|
startsWith | 74723944.0 Ops/sec |
includes | 93477600.0 Ops/sec |
Let's break down the provided benchmark and explain what's being tested.
Benchmark Definition
The benchmark is called "javascript startsWith() vs includes()" and it tests the performance of two JavaScript methods: startsWith()
and includes()
. These methods are used to check if a string contains a specific substring.
Options Compared
There are only two options being compared:
startsWith()
: This method checks if the string starts with the specified substring.includes()
: This method checks if the string contains the specified substring anywhere in it.Pros and Cons of Each Approach
startsWith()
:includes()
for large strings because it only checks a single character at a time.includes()
:startsWith()
for large strings, as it uses a more efficient algorithm to search the entire string.startsWith()
due to its more extensive substring searches.Library and Syntax
Neither of these methods relies on any specific libraries or advanced JavaScript syntax. They are built-in methods provided by the JavaScript language itself.
Other Considerations
When choosing between startsWith()
and includes()
, consider the specific requirements of your use case. If you need to check if a string starts with a substring, startsWith()
might be more efficient. However, if you need to check for a substring anywhere in the string, regardless of position, includes()
is likely a better choice.
Other Alternatives
If you don't want to use built-in methods like startsWith()
and includes()
, you can create your own implementation using JavaScript loops or regular expressions. However, this approach will generally be slower and less efficient than the built-in methods.
In terms of alternatives, there are other JavaScript libraries that provide similar functionality for string manipulation and comparison. For example, Lodash has a startsWith
method as part of its utility functions, but it's still using the underlying browser implementations for efficiency.