Benchmark: test start with v3

Script Preparation code:

function startsWith(str, a) {
	return str.substring(0, a.length) === a
}
function startsWith2(str, a) {
	return str.indexOf(a) === 0
}

Tests:

regex
/^user\.view:/.test('user.view:1337'); /^user\.list:/.test('user.view:1337')
startsWith
'user.view:1337'.startsWith('user.view:') 'user.view:1337'.startsWith('user.list:')
custom startsWith
startsWith('user.view:1337', 'user.view:') startsWith('user.view:1337', 'user.list:')
indexOf
'user.view:1337'.indexOf('user.view:') === 0 'user.view:1337'.indexOf('user.list:') === 0
substring
'user.view:1337'.substring(0, 10) === 'user.view:' 'user.view:1337'.substring(0, 10) === 'user.view:'
custom startsWith2
startsWith2('user.view:1337', 'user.view:') startsWith2('user.view:1337', 'user.list:')

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
regex
startsWith
custom startsWith
indexOf
substring
custom startsWith2

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.

I'll break down what's being tested in the provided JSON, explain the options compared, and discuss their pros and cons.

**What's being tested?**

The benchmark measures the execution time of various string manipulation functions on different JavaScript engines (in this case, Chrome). The tests compare the performance of:

1. `startsWith` (a built-in method)
2. Custom implementation of `startsWith`
3. `indexOf` (another built-in method)
4. Custom implementation of `startsWith` using a different approach (`startsWith2`)
5. `substring` (a built-in method)

**Options compared**

The options being tested are:

1. **Built-in methods**: `startsWith`, `indexOf`, and `substring`. These are standard JavaScript functions that manipulate strings.
2. **Custom implementations**: Two custom implementations of `startsWith`, one using a simple substring comparison (`startsWith`) and the other using `indexOf` (custom startsWith).

**Pros and Cons**

Here's a brief summary of the pros and cons of each option:

1. **Built-in methods**:
	* Pros: Generally faster, more efficient, and reliable.
	* Cons: May not be optimized for specific use cases or edge cases.
2. **Custom implementations**:
	* Pros: Can be tailored to specific use cases or performance requirements.
	* Cons: May require additional resources (e.g., memory), and can introduce complexity.

The custom implementation of `startsWith` using `indexOf` is likely faster than the built-in method because it avoids unnecessary string checks. However, this approach may not be suitable for all scenarios, such as when dealing with very long strings or edge cases like empty strings.

**Library usage**

There are no libraries explicitly mentioned in the benchmark definitions. The custom implementations of `startsWith` and `startsWith2` do not use any external libraries.

**Special JS features or syntax**

The benchmark uses some JavaScript features specific to certain browsers, such as:

* `Web Assembly (WASM)`. Although it's not directly used in this benchmark, Chrome 111 might be using WASM for its string manipulation functions.
* `Arrow functions` are not explicitly mentioned but could be inferred from the use of `=>`.

**Other alternatives**

If you're interested in alternative approaches or JavaScript engines, here are a few options:

1. **JavaScript engines**: Consider testing different JavaScript engines like V8 (Chrome), SpiderMonkey (Firefox), and Chakra (Edge).
2. **Language-specific optimizations**: If you want to optimize for specific languages, consider using languages with built-in string manipulation functions that can be compared.
3. **Custom implementation frameworks**: If you're interested in custom implementations, explore libraries or frameworks like `lodash` or ` Ramda`, which provide optimized string manipulation functions.

Keep in mind that the benchmark's primary goal is to compare performance across different JavaScript engines and built-in methods, making it less relevant for exploring alternative approaches or language-specific optimizations.

Related benchmarks:

test start with v3 (version: 0)

Comparing performance of: regex vs startsWith vs custom startsWith vs indexOf vs substring vs custom startsWith2

Created: 3 years ago by: Guest

Jump to the latest result

regex

startsWith

custom startsWith

indexOf

substring

custom startsWith2

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):