Benchmark: startswith vs includes

Tests:

includes
const str = "https://firebase.com/this/is/a/long/thing" str.includes("firebase")
startsWith
const str = "https://firebase.com/this/is/a/long/thing" str.startsWith("https://firebase")

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
includes
startsWith

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: yesterday)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/147.0.0.0 Safari/537.36

Browser/OS: Chrome 147 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
includes	216290752.0 Ops/sec
startsWith	52234820.0 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

LLMs can make mistakes. Check important info.

Measuring JavaScript performance can be quite complex, especially when considering the various libraries and features used in modern web development.

**Benchmark Overview**

The provided benchmark measures the performance difference between two string methods: `includes` and `startsWith`. Both methods are part of the ECMAScript standard, but they behave differently.

**Options Compared**

In this benchmark, two options are compared:

1. **`str.includes("firebase")`**: This method checks if a given string ("firebase") is present at the beginning of another string (`str`). It returns `true` if the substring is found, and `false` otherwise.
2. **`str.startsWith("https://firebase")`**: This method checks if a given string ("https://firebase") is equal to the beginning of another string (`str`). It returns `true` if the substring matches, and `false` otherwise.

**Pros and Cons**

1. **`includes` method:**
	* Pros:
		+ More flexible, as it can search for any part of the string within a larger context.
		+ Can be faster for larger strings, since it only needs to iterate through a portion of the string.
	* Cons:
		+ Less efficient when searching for an exact match at the beginning of the string.
2. **`startsWith` method:**
	* Pros:
		+ More efficient when searching for an exact match at the beginning of the string.
		+ Can be faster for smaller strings, since it only needs to compare a short substring.
	* Cons:
		+ Less flexible than `includes`, as it can only search for an exact match.

**Library Usage**

There is no explicit library usage in this benchmark. However, both methods rely on the JavaScript engine's implementation of string matching algorithms.

**Special JS Features or Syntax**

This benchmark does not involve any special JavaScript features or syntax beyond the standard `includes` and `startsWith` methods.

**Other Alternatives**

If you're looking for alternatives to these string methods, consider:

1. **Using a regular expression**: You can use the `RegExp` object to search for patterns in strings using regular expressions. This approach is more flexible than both `includes` and `startsWith`, but it may be slower due to the overhead of compiling and executing the regex pattern.
2. **Manual string searching**: If you need extreme performance, you could implement a simple manual string searching algorithm using bitwise operations or other low-level techniques.

In general, for most web development use cases, the standard `includes` and `startsWith` methods are sufficient and efficient enough. However, if you have specific requirements that necessitate more flexibility or performance, consider exploring regular expressions or alternative algorithms.

Related benchmarks:

startswith vs includes (version: 0)

Comparing performance of: includes vs startsWith

Created: 5 years ago by: Guest

Jump to the latest result

includes

startsWith

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):