使用设置精度更新变量值

value = 3.141592653589793
precision = 2
rounded_value = round(value, precision)
print(rounded_value)  # 输出: 3.14

from decimal import Decimal, getcontext

value = Decimal('3.141592653589793')
precision = 2
getcontext().prec = precision
rounded_value = value.quantize(Decimal('1.00'))
print(rounded_value)  # 输出: 3.14

let value = 3.141592653589793;
let precision = 2;
let roundedValue = value.toFixed(precision);
console.log(roundedValue);  // 输出: "3.14"

import java.math.BigDecimal;
import java.math.RoundingMode;

public class Main {
    public static void main(String[] args) {
        BigDecimal value = new BigDecimal("3.141592653589793");
        int precision = 2;
        BigDecimal roundedValue = value.setScale(precision, RoundingMode.HALF_UP);
        System.out.println(roundedValue);  // 输出: 3.14
    }
}

using System;

class Program
{
    static void Main()
    {
        double value = 3.141592653589793;
        int precision = 2;
        double roundedValue = Math.Round(value, precision);
        Console.WriteLine(roundedValue);  // 输出: 3.14
    }
}

#include <iostream>
#include <iomanip>

int main() {
    double value = 3.141592653589793;
    int precision = 2;
    std::cout << std::fixed << std::setprecision(precision) << value << std::endl;  // 输出: 3.14
    return 0;
}

let value = 3.141592653589793
let precision = 2
let roundedValue = String(format: "%.2f", value)
print(roundedValue)  // 输出: "3.14"

value = 3.141592653589793
precision = 2
rounded_value = value.round(precision)
puts rounded_value  # 输出: 3.14

$value = 3.141592653589793;
$precision = 2;
$rounded_value = round($value, $precision);
echo $rounded_value;  // 输出: 3.14