Benchmark: toFixed() vs Math.round().toString()

Script Preparation code:

var someFloat = 123.456;

Tests:

toFixed()
someFloat.toFixed();
Math.round(someFloat).toString()
Math.round(someFloat).toString();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
toFixed()
Math.round(someFloat).toString()

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36 OPR/114.0.0.0

Browser/OS: Opera 114 on Linux

View result in a separate tab

Test name	Executions per second
toFixed()	4233266.0 Ops/sec
Math.round(someFloat).toString()	5335279.0 Ops/sec

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!

Measuring performance differences between various approaches to achieve a common goal is essential in software development. In this case, we're testing two methods: `toFixed()` and `Math.round().toString()` for rounding a floating-point number.

**What are we comparing?**

We're comparing the performance of these two rounding methods on a single example value (`someFloat = 123.456`). The goal is to determine which method is faster.

**Options compared:**

*   `toFixed()`: A built-in JavaScript method that rounds a number to a fixed number of decimal places.
*   `Math.round().toString()`: A combination of the `round()` and `toString()` methods, which first rounds the number to an integer using `round()` and then converts it to a string using `toString()`.

**Pros and Cons:**

*   **toFixed():**
    *   Pros:
        +   Built-in method, so no additional library is required.
        +   Faster execution time due to optimized C++ implementation under the hood.
    *   Cons:
        +   Limited control over precision (fixed number of decimal places).
        +   May lead to inaccurate results for non-integer values with a large number of decimal places.

*   **Math.round().toString():**
    *   Pros:
        +   More flexible and accurate, as the precision is determined by the number of decimal places.
        +   Can be more readable in certain situations (e.g., when displaying currency or prices).
    *   Cons:
        +   Requires two method calls (`round()` and `toString()`), which might incur additional overhead.
        +   May not perform as well for very large numbers due to the unnecessary conversion step.

**Library usage:**

None of the methods use a library. The built-in functions (`toFixed()` and `Math.round()`) are sufficient for this benchmark.

**Special JS feature or syntax:**

There is no special JavaScript feature or syntax used in these test cases. The focus is on comparing the performance of two straightforward rounding methods.

**Other alternatives:**

Some alternative approaches to consider when rounding numbers include:

*   **Number.EPSILON**: A property that represents the smallest positive difference between 1 and any number (approximately equal to 2.22046e-16). You can use this value as a threshold for determining whether two numbers are close enough to be considered equal, allowing for more accurate comparisons.
*   **BigInt**: For very large numbers, consider using `BigInt` to avoid potential performance issues with JavaScript's built-in number type.

In summary, when rounding numbers in JavaScript, it's essential to weigh the trade-offs between precision, readability, and performance. The choice ultimately depends on your specific use case and requirements.

Related benchmarks:

toFixed() vs Math.round().toString() (version: 0)

Comparing performance of: toFixed() vs Math.round(someFloat).toString()

Created: 5 years ago by: Guest

Jump to the latest result

toFixed()

Math.round(someFloat).toString()

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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