Benchmark: String.indexOf(char) vs String.indexOf(char, position)

Script Preparation code:

window.str = 'rgba(255, 255, 255, 0.8)'

Tests:

no `position` param
const idx = str.indexOf(')')
with `position` param
const idx = str.indexOf(')', 5)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
no `position` param
with `position` param

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:121.0) Gecko/20100101 Firefox/121.0

Browser/OS: Firefox 121 on Windows

View result in a separate tab

no `position` param

1950.6M/s

with `position` param

89.8M/s

View exact numbers

Test name	Executions per second
✓ no `position` param	1,950,572,672 Ops/sec
with `position` param	89,758,088 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 benchmark and explain what's being tested, along with the pros and cons of each approach.

**Benchmark Definition**

The benchmark measures the performance difference between two approaches: calling `String.indexOf(char)` without specifying a position parameter (`char`) versus calling `String.indexOf(char, position)` with a specified position parameter (`position`).

**Options Compared**

Two options are being compared:

1. **No `position` param**: Calling `String.indexOf(char)` without specifying a position.
2. **With `position` param**: Calling `String.indexOf(char, position)` with a specified position.

**Pros and Cons of Each Approach**

1. **No `position` param**:
	* Pros: Simple, efficient, and widely supported by browsers.
	* Cons: May return -1 if the character is not found in the string from the beginning, which might be unexpected behavior for some developers.
2. **With `position` param**:
	* Pros: More predictable behavior, as it will always start searching from the specified position.
	* Cons: Requires specifying a valid position, which can lead to errors if the position is invalid or out of range.

**Library and Purpose**

There is no explicit library mentioned in the benchmark definition. However, `String.indexOf()` is a built-in JavaScript method that searches for a character within a string. The purpose of this method is to determine the index of the first occurrence of a specified character in a given string.

**Special JS Feature or Syntax**

None are explicitly mentioned. However, it's worth noting that some older browsers may have different behavior or syntax for `String.indexOf()` due to various compatibility modes or security features.

**Other Alternatives**

If you need more control over the search position or want to avoid using `String.indexOf()`, you can consider using other methods like:

1. **`str.indexOf()` with a specific index**: If you know the exact position where the character should be found, you can use this method.
2. **Regular expressions (regex)**: You can use regex patterns to search for characters within a string. This approach provides more flexibility and control over the search process.

Keep in mind that these alternatives might have different performance characteristics or may require additional setup and configuration compared to using `String.indexOf()`.

**Benchmark Preparation Code**

The provided script preparation code creates a global variable `window.str` with the value `'rgba(255, 255, 255, 0.8)'`. This is likely done to ensure that the string is set up consistently across different browsers and platforms for testing purposes.

Overall, this benchmark measures the performance difference between calling `String.indexOf(char)` without a position parameter versus calling it with a specified position. The results can help identify any potential performance differences or optimization opportunities when using these methods in your own JavaScript code.

String.indexOf(char) vs String.indexOf(char, position) (version: 0)

Comparing performance of: no `position` param vs with `position` param

Created: 2 years ago by: Guest

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