rounding float

• round

• f64

• The round method of floating point rounds to the nearest integer.

• So to round to a specific precision we can multiply-round-divide.

#![allow(clippy::approx_constant)]
#![allow(clippy::unnecessary_cast)]
#![allow(clippy::excessive_precision)]

fn main() {
    let pi = 3.1415926535897932384626433;
    println!("{pi}");
    println!("{:.2}", pi);
    let rpi = (pi * 100.0 as f64).round() / 100.0;
    println!("{rpi}");

    let xpi = (pi * 10000.0 as f64).round() / 10000.0;
    println!("{xpi}");

    println!();

    let x: f32 = 3.14159;
    println!("{x}");
    println!("{:.2}", x);
    let y = (x * 100.0).round() / 100.0;
    println!("{y}");
}

3.141592653589793
3.14
3.14
3.1416

3.14159
3.14
3.14