Benchmark: roundDecimal: pow() vs. toPrecision()

Script Preparation code:

function roundDecimalPow(value, decimals) {
  const factor = Math.pow(10, decimals);
  return Math.round(value * factor) / factor;
}

function roundDecimalToPrecision(value, decimals) {
  return parseFloat(value.toPrecision(decimals))
}

Tests:

roundDecimalPow()
roundDecimalPow(Math.random(), 2)
roundDecimalToPrecision()
roundDecimalToPrecision(Math.random(), 2)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
roundDecimalPow()
roundDecimalToPrecision()

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark.

**Benchmark Definition**

The benchmark is defined by two functions: `roundDecimalPow` and `roundDecimalToPrecision`. These functions are used to round decimal numbers in JavaScript.

*   `roundDecimalPow(value, decimals)` takes a value and an integer number of decimals as input. It calculates the rounded decimal value using the formula: `(value * Math.pow(10, decimals)) / 10^decimals`.
*   `roundDecimalToPrecision(value, decimals)` takes a string or number value and an integer number of decimals as input. It returns the rounded decimal value by calling `parseFloat` with the `toPrecision` method.

**Options Compared**

The benchmark compares two approaches:

1.  Using the `Math.pow` function to calculate the power.
2.  Using the `toPrecision` method to round a number.

**Pros and Cons of Each Approach**

*   **Using Math.pow**:
    *   Pros: This approach is more efficient because it uses a built-in JavaScript function, which can be optimized by the engine.
    *   Cons: This approach can lead to potential precision issues due to floating-point arithmetic limitations in JavaScript.

*   **Using toPrecision**:
    *   Pros: This approach provides precise control over rounding decimals and can avoid potential precision issues associated with floating-point arithmetic.
    *   Cons: This approach is slower because it involves an extra string conversion step and potentially a more complex algorithm. Additionally, the `toPrecision` method may not work correctly for all inputs (e.g., negative numbers).

**Library Used**

There are no external libraries used in this benchmark.

**Special JavaScript Features or Syntax**

No special JavaScript features or syntax is used beyond standard JavaScript.

Now let's look at the test cases:

*   The first test case, `roundDecimalPow(Math.random(), 2)`, tests the `roundDecimalPow` function with random input values.
*   The second test case, `roundDecimalToPrecision(Math.random(), 2)`, tests the `roundDecimalToPrecision` function with random input values.

**Other Alternatives**

Some alternative approaches for rounding decimals in JavaScript include:

1.  Using a library like [decimal.js](https://github.com/MikeMhesse/decimal.js): This library provides decimal arithmetic and can be used to round decimals accurately.
2.  Implementing a custom rounding algorithm using bitwise operations or shift operators.

For production code, you may want to consider using established libraries for precise decimal arithmetic, especially when working with financial or scientific applications where precision is critical.

The benchmark results show the raw UA string, browser, device platform, operating system, executions per second, and test name. This information can be used to analyze performance differences between the two approaches.

**Benchmark Preparation Code**

Here's a breakdown of what each section does in the benchmark preparation code:

*   The `roundDecimalPow` function calculates the rounded decimal value using the formula `(value * Math.pow(10, decimals)) / 10^decimals`.
*   The `roundDecimalToPrecision` function calls `parseFloat` with the input string's `toPrecision` method to round the number.
*   The script preparation code defines both functions.

Related benchmarks:

roundDecimal: pow() vs. toPrecision() (version: 0)

Comparing performance of: roundDecimalPow() vs roundDecimalToPrecision()

Created: 5 years ago by: Guest

Jump to the latest result

roundDecimalPow()

roundDecimalToPrecision()

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):