Benchmark: Math.round vs Number.isInteger

Tests:

Number.isInteger (true)
Number.isInteger(1234567891122345)
Number.isInteger (false)
Number.isInteger(123456789112234.5)
Math.round (integer)
Math.round(1234567891122345)
Math.round (non-integer)
Math.round(123456789112234.5)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Number.isInteger (true)
Number.isInteger (false)
Math.round (integer)
Math.round (non-integer)

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/118.0.0.0 Safari/537.36

Browser/OS: Chrome 118 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Number.isInteger (true)	10997020.0 Ops/sec
Number.isInteger (false)	11091196.0 Ops/sec
Math.round (integer)	10707008.0 Ops/sec
Math.round (non-integer)	10644279.0 Ops/sec

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

LLMs can make mistakes. Check important info.

**Benchmark Explanation**

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks. The provided JSON represents a benchmark titled "Math.round vs Number.isInteger". This benchmark compares the performance of two approaches: checking if a number is not an integer using `Number.isInteger` before rounding with `Math.round`, and rounding the number directly.

**Comparison Options**

The benchmark tests four test cases:

1. Checking if a large integer (1234567891122345) is not an integer using `Number.isInteger`.
2. Checking if another large integer (123456789112234.5) is not an integer using `Number.isInteger`.
3. Rounding the first large integer with `Math.round` to get an integer result.
4. Rounding the second large integer with `Math.round` to get a non-integer result.

**Pros and Cons**

The two approaches have different pros and cons:

* **Checking if a number is not an integer before rounding:**
	+ Pros:
		- Can be faster for small integers, as it avoids the overhead of rounding.
		- Reduces the risk of precision errors due to floating-point arithmetic.
	+ Cons:
		- May incur additional overhead due to the `Number.isInteger` check.
		- May not be suitable for large integers or high-performance applications where rounding is necessary.
* **Rounding directly with Math.round:**
	+ Pros:
		- Can be faster for large integers, as it avoids the overhead of the `Number.isInteger` check.
		- Suitable for high-performance applications where precision is not critical.
	+ Cons:
		- May result in precision errors due to floating-point arithmetic.
		- May require additional checks to ensure correctness.

**Library and Special Features**

The benchmark uses the `Number` object, which is a built-in JavaScript object that provides functions for working with numbers. The `Number.isInteger()` method is also used, which returns true if the given number is an integer (i.e., has no fractional part).

There are no special features or syntax used in this benchmark.

**Other Alternatives**

If you want to write your own JavaScript microbenchmarking test, here's an example of how you could structure it:
```javascript
const num1 = 1234567891122345;
const num2 = 123456789112234.5;

const isIntegerTest = (num) => {
  return Number.isInteger(num);
};

const roundTest = (num) => {
  return Math.round(num);
};

// Test cases
console.time('isInteger');
for (let i = 0; i < 100000; i++) {
  isIntegerTest(num1);
}
console.timeEnd('isInteger');

console.time('round');
for (let i = 0; i < 100000; i++) {
  roundTest(num1);
}
console.timeEnd('round');

console.time('isInteger2');
for (let i = 0; i < 100000; i++) {
  isIntegerTest(num2);
}
console.timeEnd('isInteger2');

console.time('round2');
for (let i = 0; i < 100000; i++) {
  roundTest(num2);
}
console.timeEnd('round2');
```
This code uses `console.time()` and `console.timeEnd()` to measure the execution time of each test case. You can run this code in a JavaScript environment or create your own benchmarking framework to compare different approaches.

Related benchmarks:

Math.round vs Number.isInteger (version: 0)

Is it faster to check whether a number is not an integer before rounding

Comparing performance of: Number.isInteger (true) vs Number.isInteger (false) vs Math.round (integer) vs Math.round (non-integer)

Created: one year ago by: Guest

Jump to the latest result

Number.isInteger (true)

Number.isInteger (false)

Math.round (integer)

Math.round (non-integer)

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):