Benchmark: String Match123 - MeasureThat.net

Tests:

indexOf
var found = 'High chance of stuff falling from the sky!'.slice(0, 4).toLowerCase().indexOf('high') > -1;
Regex
var found = 'High chance of stuff falling from the sky!'.match(/^(high)(.*)/i);
equals
found = 'High chance of stuff falling from the sky!'.slice(0, 4).toLowerCase() === 'high';

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
indexOf
Regex
equals

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

I'll break down the benchmark and its test cases to explain what's being tested, compared, and their pros and cons.

**Benchmark Overview**

The `MeasureThat.net` website provides a platform for users to create and run JavaScript microbenchmarks. In this case, we have three individual test cases: `indexOf`, `Regex`, and `equals`. The benchmark is designed to compare the performance of these different approaches in finding a specific substring or pattern within a larger string.

**Test Cases**

1. **`indexOf`**: This test case checks the performance of the `indexOf()` method, which returns the lowest index at which a specified value can be found in an array element.

```javascript
var found = 'High chance of stuff falling from the sky!'.slice(0, 4).toLowerCase().indexOf('high') > -1;
```

The pros of using `indexOf()` include:
   * It's a widely supported method across different browsers and environments.
   * It returns a specific index value if found.

However, the cons include:
   * It can be slower for very large strings or arrays due to the algorithm used.
   * It may return `-1` if the specified value is not found, which can lead to additional checks.

2. **`Regex`**: This test case checks the performance of regular expressions (regex) in finding a specific pattern within a larger string.

```javascript
var found = 'High chance of stuff falling from the sky!'.match(/^(high)(.*)/i);
```

The pros of using regex include:
   * It provides a powerful and flexible way to match patterns.
   * It can handle complex matching scenarios with variables or anchors.

However, the cons include:
   * Regex can be slower due to the overhead of parsing and compiling the pattern.
   * It may not support all edge cases or Unicode characters.

3. **`equals`**: This test case checks the performance of a simple equality check using `===`.

```javascript
found = 'High chance of stuff falling from the sky!'.slice(0, 4).toLowerCase() === 'high';
```

The pros of using `===` include:
   * It's often faster and more efficient than other methods due to its simplicity.
   * It provides a straightforward way to check for equality.

However, the cons include:
   * It can be slower if used with large or complex strings.
   * It may not provide meaningful results in cases where precision is required.

**Library and Special Features**

There are no libraries mentioned in this benchmark. The code relies solely on built-in JavaScript methods and syntax.

However, it's worth noting that the `match()` method uses a regex engine internally to match patterns, so while there isn't an explicit library used, the underlying mechanics are still influenced by regex concepts.

**Alternative Approaches**

Some alternative approaches for these test cases include:

* **`includes()`**: This is a more modern and efficient way to check if a string includes a certain substring. It's supported in most browsers starting from ES6.
* **`toString().search()`**: This method uses the `search()` function, which is similar to `indexOf()`, but returns `-1` if no match is found instead of returning `-1`.
* **`includes()` with flags**: In some cases, using `regex` flags (like `i` for case-insensitive matching) can improve performance.
* **`String.prototype.localeCompare()`**: This method provides a locale-dependent comparison that might be faster in certain scenarios.

Keep in mind that the best approach often depends on the specific requirements and constraints of your use case.

Latest run results:

Run details: (Test run date: 5 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.142 Safari/537.36

Browser/OS: Chrome 75 on Windows

View result in a separate tab

Test name	Executions per second
indexOf	25951028.0 Ops/sec
Regex	3030599.5 Ops/sec
equals	1154885.4 Ops/sec

Related benchmarks:

String Match123 (version: 0)

Comparing performance of: indexOf vs Regex vs equals

Created: 5 years ago by: Guest

Jump to the latest result

indexOf

Regex

equals

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):