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

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

Autogenerated LLM Summary (model llama3.2:3b, generated 2 months 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.

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 2 months ago):