Benchmark: Parsing args - MeasureThat.net

Script Preparation code:

var args = [
    "ru=http://localhost:9001",
    "us=http://localhost:9002",
    "ab=http://localhost:9003",
    "cd=http://localhost:9004",
    "ef=http://localhost:9005",
    "gh=http://localhost:9006",
    "ih=http://localhost:9007",
    "kl=http://localhost:9008",
    "mn=http://localhost:9009",
    "op=http://localhost:9010",
    "qr=http://localhost:9011",
    "st=http://localhost:9012",
    "uv=http://localhost:9013",
    "wx=http://localhost:9014",
    "yz=http://localhost:9015",
    "aa=http://localhost:9016",
    "bb=http://localhost:9017",
    "cc=http://localhost:9018",
    "dd=http://localhost:9019",
    "ee=http://localhost:9020",
]

Tests:

Regex.test
var regex = /[a-zA-Z]{2}=.*/ var result = args.filter(_ => regex.test(_)) console.log(result);
indexOf === 1
var result = args.filter(_ => _.indexOf("=") === 1) console.log(result);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Regex.test
indexOf === 1

Fastest: N/A

Slowest: N/A

Latest 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.

**Benchmark Definition JSON**

The provided JSON represents a benchmark named "Parsing args". This benchmark measures the performance of two different approaches to parsing command-line arguments in JavaScript.

The Script Preparation Code defines an array `args` containing 30 URLs, which will be used as input for the test cases. The Html Preparation Code is empty, indicating that no HTML is involved in this benchmark.

**Options Compared**

Two options are compared:

1. **Regex.test**: This approach uses a regular expression to check if each URL contains an equal sign (`=`). The `Regex.test()` method returns a boolean value indicating whether the input string matches the pattern.
2. **indexOf === 1**: This approach uses the `indexOf` method to find the index of the first occurrence of `"="` in each URL and then checks if it's equal to 1.

**Pros and Cons**

Here are some pros and cons for each approach:

* **Regex.test**:
	+ Pros: Can be more efficient than using `indexOf`, as it's implemented in native code.
	+ Cons: May be slower for very large inputs, as regular expressions can be computationally expensive to create and match.
* **indexOf === 1**:
	+ Pros: Typically faster than `Regex.test` for simple cases, as it's a built-in method that doesn't require creating a pattern object.
	+ Cons: Can be slower for very large inputs, as it may require scanning the entire string to find the index.

**Library and Purpose**

In both test cases, no external libraries are used. The `Regex.test` approach relies on JavaScript's native `RegExp` API, while the `indexOf === 1` approach uses a built-in method.

**Special JS Feature or Syntax**

There is no special JavaScript feature or syntax used in these test cases. They only rely on standard JavaScript methods and operators.

**Other Alternatives**

If you were to rewrite this benchmark using alternative approaches, some options might include:

* Using `String.prototype.includes()` instead of `indexOf === 1`, which would provide a more modern and efficient way to check for substring presence.
* Implementing a custom parsing algorithm that's optimized for performance, potentially using techniques like caching or memoization.

**Benchmark Preparation Code**

To prepare this benchmark, you would create an array of URLs (`args`) and define two test cases:

```javascript
// Define the input array
const args = [
  // ... (30 URLs)
];

// Test case 1: Regex.test
function testRegex() {
  const regex = /[a-zA-Z]{2}=.*/;
  return args.filter((url) => regex.test(url));
}

// Test case 2: indexOf === 1
function testIndexOf() {
  return args.filter((url) => url.indexOf("=") === 1);
}
```

To run the benchmark, you would call one of these functions and measure its performance using a tool like MeasureThat.net.

Related benchmarks:

Parsing args (version: 0)

Comparing performance of: Regex.test vs indexOf === 1

Created: 3 years ago by: Guest

Jump to the latest result

Regex.test

indexOf === 1

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):