Benchmark: javascript startsWith() vs includes()

Tests:

startsWith
const str = "utm_source" str.startsWith("utm_")
includes
const str = "utm_source" str.includes("utm_")

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
startsWith
includes

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/144.0.0.0 Safari/537.36

Browser/OS: Chrome 144 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
startsWith	100485752.0 Ops/sec
includes	199727584.0 Ops/sec

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

LLMs can make mistakes. Check important info.

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:

1. `startsWith()`: This method checks if the string starts with the specified substring.
2. `includes()`: This method checks if the string contains the specified substring anywhere in it.

**Pros and Cons of Each Approach**

*   **`startsWith()`:**
    *   Pros:
        *   More efficient for certain use cases, as it returns early when the string does not start with the substring.
        *   Can be more readable and easier to maintain in some situations.
    *   Cons:
        *   May not work correctly if the string is empty or null.
        *   Might be slower than `includes()` for large strings because it only checks a single character at a time.
*   **`includes()`:**
    *   Pros:
        *   Works correctly even when the string is empty or null.
        *   Can be faster than `startsWith()` for large strings, as it uses a more efficient algorithm to search the entire string.
    *   Cons:
        *   Might be slower than `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.

Related benchmarks:

javascript startsWith() vs includes() (version: 0)

Comparing performance of: startsWith vs includes

Created: 4 years ago by: Guest

Jump to the latest result

startsWith

includes

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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