Question

This question is unlikely to help any future visitors; it is only relevant to a small geographic area, a specific moment in time, or an extraordinarily narrow situation that is not generally applicable to the worldwide audience of the internet. For help making this question more broadly applicable, visit the help center.

Closed 11 years ago.

I m having trouble writing a method to calculate the total of some orders for a university project. Eclipse says there s an error, detailing only that the + is an invalid AssignmentOperator.

一些细节:

There s no privacy issues.
quantity is an int.
getPrice() returns a double.
total is a double

这种做法可能的确很简单,但因为如此,寻找答案非常困难。

public double calculateTotal(){
    for(OrderItem currentItem:items){
        for(int i=0;i<currentItem.quantity;i++){
            total+currentItem.product.getPrice();
        }
    }
    return total;
}

Answer 1

我认为需要<代码>+=:

public double calculateTotal(){
    for(OrderItem currentItem:items){
        for(int i=0;i<currentItem.quantity;i++){
            total += currentItem.product.getPrice();
        }
    }
    return total;
}

在你的例子中,你只重复了两点,没有结果。你们需要把结果分配给一个变量。使用<代码>+=为 Total = Total + currentItem.product.GetPrice();

您还可能需要将<代码>完全变量初步化;但可能的话,该代码在你的班次中其他部分。

Answer 2

你们不能只增加两条价值观,而不必这样做。我怀疑你的话。

        total += currentItem.product.getPrice();

Answer 3

页: 1 使用<代码>+=:

total += currentItem.product.getPrice();

友情链接