Benchmark: indexof operator performance

Script Preparation code:

var userAgent = navigator.userAgent.toLowerCase();

Tests:

negative
userAgent.indexOf("bot") > -1
not equal
userAgent.indexOf("bot") != -1

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
negative
not equal

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

**What is tested?**

The provided benchmark tests the performance of the `indexOf` method in JavaScript, specifically when searching for the presence of certain substrings within a user agent string. The test cases compare two approaches:

1. Checking if the index of the substring is not equal to -1 (`indexOf("bot") != -1`).
2. Checking if the index of the substring is greater than -1 (`indexOf("bot") > -1`).

**Options compared**

The benchmark tests the performance of these two options:

* Option 1: `indexOf("bot") != -1`
* Option 2: `indexOf("bot") > -1`

**Pros and cons of each approach**

Option 1 (`indexOf("bot") != -1`) is a more traditional way of checking for the presence of a substring in JavaScript. However, it can be slower than option 2 because it involves two steps:

1. Calculate the index of the substring.
2. Check if the index is not equal to -1.

Option 2 (`indexOf("bot") > -1`) is a more optimized approach because it eliminates the need for the second step. However, some older browsers may behave unexpectedly when using this method, as they may return an empty string instead of -1 in certain cases.

**Library and purpose**

In this benchmark, no specific library is used beyond the built-in `indexOf` method. The `navigator.userAgent` property returns a string containing information about the user's browser, device, and operating system.

**Special JS feature or syntax**

There are no special JavaScript features or syntax used in this benchmark.

**Other considerations**

* The use of `toLowerCase()` in the script preparation code is likely done to ensure that the comparison is case-insensitive. This is a good practice when working with user agent strings, as they can contain uppercase or lowercase characters.
* The benchmark uses the `RawUAString` property to display the actual user agent string returned by the browser. This can be useful for debugging and understanding how the browser handles user agent strings.

**Alternatives**

Other alternatives for testing the performance of the `indexOf` method might include:

* Using a different substring or using a longer substring to test performance at higher scales.
* Adding more test cases, such as checking for multiple substrings or handling edge cases like empty strings or null inputs.
* Comparing the performance of other methods, such as `includes()` (introduced in ECMAScript 2015) or custom implementation using regular expressions.

I hope this explanation helps! Let me know if you have any further questions.

Related benchmarks:

indexof operator performance (version: 0)

Comparing performance of: negative vs not equal

Created: 3 years ago by: Guest

Jump to the latest result

negative

not equal

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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