“作业的左侧必须是变量”

Question

我收到错误消息“分配的左侧必须是变量”，其他地方是else（itemNumber＆gt; = 15）

import java.util.Scanner;

public class Ch3Asg
{

    public static void main(String[] args)

    {
        // Variables
            Scanner input = new Scanner(System.in);
            int itemNumber = 0;
            double shippingCost = 0;

        // Items Purchased
            System.out.println("How many items did you purchase? ");
            itemNumber = Integer.parseInt(input.nextLine());

        // One Item Purchased
            if ( itemNumber == 1 )
            {
                shippingCost = 2.99;
            }   

        // 2-5 Items Purchased
            else if ( itemNumber >= 2 && itemNumber <= 5 );
            {
                shippingCost = 2.99 + 1.99 * (itemNumber - 1);
            }

        // 5-15 Items Purchased
            if ( itemNumber > 5 && itemNumber < 15)
            {
                shippingCost = 2.99 + 1.99 * (itemNumber - 1) + 1.49 * (itemNumber - 5);
            }
        // More Than 15 Items Purchased
            else ( itemNumber >= 15 )
            {
                shippingCost = 2.99 + 1.99 * (itemNumber - 1) + 1.49 * (itemNumber - 5)
                        + .99 * (itemNumber - 14);
            }
        // Display Cost
            System.out.printf("Shipping Cost is: $%.2f", shippingCost);
    }

}

Answer 1

else (boolean statement)毫无意义。我想你忘记了if：

else ( itemNumber >= 15 )

应该是

else if ( itemNumber >= 15 )

否则，如果它代表最后一个默认选项，则可能只是：

else {
   //..
}

Answer 2

else构造不接受表达式，所以

    else ( itemNumber >= 15 )

在语法上是错误的。

您需要使用else if代替

    else if ( itemNumber >= 15 )