java - java中如何四舍五入到小数点后两位

Question

这个问题已经有答案了:

How do I round a double to two decimal places in Java? [duplicate] (21 个回答)

已关闭 8 年前。

最终双倍 YearDep= 0.15；//这是汽车每年损失之前的值(value)

     double HybridDepreciation= HybridCarCost * Math.pow(1-YearDep,5);
     double HybridFuelCost=(Miles*5*GasCost)/HybridCarMPG;

     double GasPowerDepreciation=GasPowerCost * Math.pow(1-YearDep,5);
     double GasPowerFuelCost=(Miles *5*GasCost)/GasPowerMPG;

     double HybridTotalCost=HybridCarCost - HybridDepreciation + HybridFuelCost;
     double GasPowerTotalCost= GasPowerCost - GasPowerDepreciation + GasPowerFuelCost;

     System.out.printf("The total cost for the " + HybridName + " " + "is" +" $"+ HybridTotalCost);

     System.out.println();
     System.out.printf("The total cost for the " + GasPowerName + " "+ "is" + " $"+ GasPowerTotalCost);

Answer 1

使用DecimalFormat为此:

DecimalFormat df = new DecimalFormat(".00");
System.out.printf("The total cost for the " + HybridName + " " + "is" +" $"+ df.format(HybridTotalCost));
 System.out.println();
 System.out.printf("The total cost for the " + GasPowerName + " "+ "is" + " $"+ df.format(GasPowerTotalCost));

或者你可以使用

String.format("The total cost for the  %s is $%.2f", HybridName ,HybridTotalCost)