为什么当我尝试将双倍到小数点后 2 位时会出现此错误

Question

我正在创建一个简单的程序来计算运行汽车的成本。该程序运行良好，但我想看看是否可以获得小数点后 2 位的最终答案。我尝试使用'%8.2f'的东西，但它说no method could be found for println(string, double)

这是我的代码：

/* Program to calculate the running cost of car */
import java.util.Scanner;
public class RunningCosts {
    public static void main(String[] args) {
        final int TOTAL_DISTANCE = 100000;
        Scanner in = new Scanner(System.in);
        System.out.print("Enter the car cost: ");
        double carCost = in.nextDouble();
        System.out.print("Enter the service cost: ");
        double serviceCost = in.nextDouble();
        System.out.print("Enter the service interval: ");
        double serviceInterval = in.nextDouble();
        System.out.print("Enter km per litre: ");
        double kmPerLitre = in.nextDouble();
        System.out.print("Enter the fuel cost per litre: ");
        double fuelCostPerLitre = in.nextDouble();

        double serviceTotal = (TOTAL_DISTANCE/serviceInterval) * serviceCost;
        System.out.println( "Service Total: " + serviceTotal); //Here
        double fuelCost = (TOTAL_DISTANCE/kmPerLitre) * fuelCostPerLitre;
        System.out.println( "Fuel Cost: " + fuelCost); //Here
        double totalCost = carCost + fuelCost + serviceTotal;
        System.out.println( "Estimated Cost: " + totalCost); //And here
    }
}

注释的行是我希望格式化为小数点后 2 位的内容

Answer 1

按照@shmosel建议使用 printf，或使用String.format

：

System.out.println( "Service Total: " + String.format("%.2f", serviceTotal));

有关更多使用示例，请参阅此页面。