我是一个新的Java学生。我是Olderrrrr，一生我无法弄清楚这一点。我们尚未完成数组，所以这不是问题的一部分。
此程序应在一个例外情况下运行。我需要实现一个段循环，以验证这种风味和/或尺寸的选择。
import java.util.Scanner;
public class Cheesecake2 {
public static void main(String[] args) {
// TODO Auto-generated method stub
//variable declarations
//Total cost based on calculation of size * flavor
double pricePerInch = 0.0; //cost per inch
double cost = 0.0; //cost calculation base on flavor and size selections
double inches = 0.0; //inches per size
double totalCost = 0.0; //accumulator to hold value of items selected
Scanner scnr = new Scanner(System.in);
String flavor = ""; //flavor choice entered by user
String size = ""; //size choice entered by user
String addAnother; //Holds 'yes' or 'no'
do {
System.out.println("Enter the flavor you'd like (plain, caramel, chocolate, raspberry, or strawberry:)");
flavor = scnr.nextLine();
//Calculate users total cost based on flavor and size choices
if (flavor.equalsIgnoreCase("plain")) { //plain cheesecake
pricePerInch = 0.50;
}
else if (flavor.equalsIgnoreCase("caramel")) { //caramel cheesecake
pricePerInch = 0.75;
}
else if (flavor.equalsIgnoreCase("chocolate")) { //chocolate cheesecake
pricePerInch = 0.85;
}
else if (flavor.equalsIgnoreCase("raspberry")) { //raspbery cheesecake
pricePerInch = 1.15;
}
else if (flavor.equalsIgnoreCase("strawberry")) { //strawberry cheesecake
pricePerInch = 1.25;
}
else {
System.out.println("That's not a valid flavor, please enter: plain, caramel, chocolate, raspberry, or strawberry.");
}
while (flavor != ("plain") || flavor != ("caramel") ||flavor != ("chocolate") ||flavor != ("raspberry") ||flavor != ("strawberry")); {
System.out.println("Please enter a valid flavor choice");
flavor = scnr.nextLine();
}
//ask user for size input
System.out.println("Enter the size you'd like (bite size, small, or large)");
size = scnr.nextLine();
//Prompt user for a size selection
if (size.equalsIgnoreCase("bite size")) { //bite size
inches = 3; //size in inches
}
else if (size.equalsIgnoreCase("small")) { //small
inches = 6; //size in inches
}
else if (size.equalsIgnoreCase("large")) { //large
inches = 9; //size in inches
}
else {
System.out.println("I'm sorry " + size + " isn't one our size options. Please choose: bite size, small, or large.");
}
cost = pricePerInch * inches; //calculate cheesecake cost base on flavor and size selections
System.out.printf(flavor + " " + size + " cheesecake" + ": $%.2fn",cost);
totalCost += cost; //add cheesecake cost to accumulator totalCost
//Prompt user if they want to add to their order?
System.out.println("Would you like to add another cheesecake to your order? Enter yes or no");
addAnother = scnr.nextLine();
} while (addAnother.equals("yes"));
//Display total sales
System.out.printf("The total cost for your order is" + ": $%.2fn",totalCost);
}
}
但是，无论我放在哪里或如何设置它，它都会打破其他内容，并且只会经过一次迭代。
任何建议将不胜感激！
对其进行了修改：
public static void main( final String[] args )
{
// `Scanner` should be closed... this will close it up in the end...
try ( final Scanner scnr = new Scanner( System.in ) )
{
// variable declarations
double totalCost = 0.0; // accumulator to hold value of items selected
String flavor; // flavor choice entered by user
String size; // size choice entered by user
String addAnother; // Holds 'yes' or 'no'
// infinte loop with a label, will use `break label` to get out of it...
addAnotherLoop: while ( true )
{
// Total cost based on calculation of size * flavor
// moved here, because the initialization
double pricePerInch = 0.0; // cost per inch
double inches = 0.0; // inches per size
double cost = 0.0; // cost calculation base on flavor and size selections
// ask user for flavour input
System.out.println( "Enter the flavor you'd like:n" +
"(plain, caramel, chocolate, raspberry, or strawberry)" );
do
{
flavor = scnr.nextLine();
if ( "plain".equalsIgnoreCase( flavor ) )
{ // plain cheesecake
pricePerInch = 0.50;
}
else if ( "caramel".equalsIgnoreCase( flavor ) )
{ // caramel cheesecake
pricePerInch = 0.75;
}
else if ( "chocolate".equalsIgnoreCase( flavor ) )
{ // chocolate cheesecake
pricePerInch = 0.85;
}
else if ( "raspberry".equalsIgnoreCase( flavor ) )
{ // raspbery cheesecake
pricePerInch = 1.15;
}
else if ( "strawberry".equalsIgnoreCase( flavor ) )
{ // strawberry cheesecake
pricePerInch = 1.25;
}
else
{
System.out.println( "That's not a valid flavor, please enter: plain," +
"caramel, chocolate, raspberry, or strawberry." );
}
}
// if no valid flavour was entered, `pricePerInch` is still 0...
while ( 0.0 == pricePerInch );
// ask user for size input
System.out.println( "Enter the size you'd like:n(bite size, small, or large)" );
do
{
size = scnr.nextLine();
// Prompt user for a size selection
if ( "bite size".equalsIgnoreCase( size ) )
{ // bite size
inches = 3; // size in inches
}
else if ( "small".equalsIgnoreCase( size ) )
{ // small
inches = 6; // size in inches
}
else if ( "large".equalsIgnoreCase( size ) )
{ // large
inches = 9; // size in inches
}
else
{
System.out.printf( "I'm sorry %s isn't one our size options.n" +
"Please choose: bite size, small, or large.n",
size );
}
}
// if no valid size was entered, `inches` is still 0...
while ( 0.0 == inches );
// calculate cheesecake cost base on flavor and size selections
cost = pricePerInch * inches;
System.out.printf( "%s %s cheesecake: $%.2f%n", flavor, size, cost );
// add cheesecake cost to accumulator totalCost
totalCost += cost;
// Prompt user if they want to add to their order?
System.out.println( "Would you like to add another cheesecake to your order?" );
do
{
System.out.print( "Enter yes or no: " );
addAnother = scnr.nextLine();
// if no, exit the outer loop
if ( "no".equalsIgnoreCase( addAnother ) )
{
break addAnotherLoop;
}
}
// if not yes, continue the loop
while ( ! "yes".equals( addAnother ) );
}
// Display total sales
System.out.printf( "The total cost for your order is: $%.2fn", totalCost );
}
}