Benchmark: Number vs Regex - MeasureThat.net

Script Preparation code:

window.case1 = new Proxy({}, {
  get(t, p, r) {
    if (Number.isInteger(Number(p))) {
      return +p
    }
    else {
      return Reflect.get(t, p, r)
    }
  }
});
window.case2 = new Proxy({}, {
  get(t, p, r) {
    if (/^-?[0-9]+$/.test(p)) {
      return +p
    }
    else {
      return Reflect.get(t, p, r)
    }
  }
});
window.gabage1 = 0;
window.gabage2 = 0;

Tests:

Number
for (let i = 0; i < 1e6;i++) { gabage1 =+ case1[i]; }
Regex
for (let i = 0; i < 1e6;i++) { gabage2 += case2[i]; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Number
Regex

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.

The provided benchmark measures the performance difference between using the `Number.isInteger` function and a regular expression (`/^-?[0-9]+$/.test`) to check if a string represents an integer.

Let's break down what's being tested:

1. **Proxy Objects**: The script preparation code creates two proxy objects, `case1` and `case2`, using the Proxy constructor. A proxy object is a special type of object that allows you to intercept and modify access to its properties. In this case, we're using them as test subjects.
2. **Checking for Integer Strings**: Inside each proxy object, there's a `get` trap function that checks if the accessed property (`p`) is an integer string. For `case1`, it uses `Number.isInteger(Number(p))`, while for `case2`, it uses a regular expression `/^-?[0-9]+$/.test(p)`. Both methods aim to return the numeric value of the string (if it's an integer) or the original property value (if it's not an integer).
3. **Benchmark Test Cases**: There are two individual test cases:
	* "Number": It iterates 1 million times, assigning the result of `case1[i]` to a local variable (`gabage1`). The goal is to measure how fast this assignment happens.
	* "Regex": It iterates 1 million times, adding the result of `case2[i]` to another local variable (`gabage2`). Again, the aim is to measure performance.

Now, let's discuss the pros and cons of using `Number.isInteger` versus a regular expression:

**Pros of `Number.isInteger`:**

* **Readability**: The code is straightforward and easy to understand.
* **Performance**: It's likely faster since it's a built-in function optimized for performance.

**Cons of `Number.isInteger`:**

* **Limited support**: Some older browsers might not have this function, or they might behave differently due to how JavaScript engines implement it.
* **Platform-specific behavior**: On some platforms (e.g., Windows), `Number.isInteger` returns `true` for NaN (Not a Number) values.

**Pros of regular expression:**

* **Flexibility**: The regex can be used to match more complex patterns, not just simple integer strings.
* **Wide browser support**: Regular expressions are widely supported across browsers and platforms.

Cons:

* **Slower performance**: Regex operations can be slower than direct checks using `Number.isInteger`.
* **Complexity**: The code might become harder to read and maintain due to the added complexity of regular expression syntax.

**Special consideration for Safari 16:**

The benchmark result shows that Safari 16 performs slightly better with the "Regex" test case. It's essential to note that this is likely due to the way Safari 16 optimizes its JavaScript engine, which might provide an edge in terms of regex performance.

Now, if you're wondering about alternatives, here are a few:

* **Use `parseInt` instead**: You can use `parseInt()` to parse strings into integers. This would simplify your test cases and eliminate the need for proxies.
* **Consider using a dedicated integer checking library**: If you find yourself frequently working with string-to-integer conversions, consider using a specialized library like `lodash.isInteger()`.
* **Optimize regex patterns**: For more complex use cases, you might want to explore optimized regex patterns or libraries that provide better performance.

I hope this explanation helps! Let me know if you have any further questions.

Related benchmarks:

Number vs Regex (version: 0)

Comparing performance of: Number vs Regex

Created: 2 years ago by: Guest

Jump to the latest result

Number

Regex

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):