Variable not updating based on a change of another

Question

In my program I have a method calculateCost(), which gets the cost of a truck based on the minimum temperature of said truck.

public double calculateCost() {

    int minimumTemperature = this.getTemperature();

    System.out.println("Temp is: " + minimumTemperature);

    double costOfTruck = 900 + 200 * (Math.pow(0.7, (minimumTemperature / 5))); 

    System.out.println("Cost is: " + costOfTruck);

    return costOfTruck;
}

When this method is executed, the minimumTemperature correctly changes as shown in the console, however, the costOfTruck doesn't change when the minimumTemperature is changed.

Answer 1

如果minimumTemperature <5，则由于整数除法， minimumTemperature / 5将等于零，而Math.pow(0.7, (minimumTemperature / 5)将等于1，因此请尝试使用双数值类型

double costOfTruck = 900 + 200 * (Math.pow(0.7, (minimumTemperature / 5.0)));