我的代码的这一部分无法正常工作。我需要从A，B或X菜单中选择，然后输入一个小句子作为描述（多个）成本的数字。我可以完美地输入所有数据并返回菜单（仅在输入X时退出）。但是变量damageDesc的返回字符串只是抓住空格之前的第一个单词。我整晚都试过这个，仍然无法让它返回字符串中的所有单词。如果有人可以提供帮助，这是代码。谢谢！
do {
System.out.println("Damage Repair / Traffic Infringement Data Entry "+
"Menu");
System.out.println("-------------------------------------------------"+
"---");
System.out.println();
System.out.println("A - Record Damage Repair Details");
System.out.println("B - Record Traffic Infringement Details");
System.out.println("X - Exit");
System.out.println();
System.out.print("Enter your selection (A/B/X):");
menuOption = console.next().charAt(0);
switch (menuOption) {
case 'A':
case 'a':
System.out.print("Enter description of damage repair: ");
damageDesc = console.next();
console.nextLine();
System.out.print("Enter repair cost: ");
damageCost= console.nextDouble();
//Place damage description and cost on seperate lines
damageDescFinal = String.format(damageDescFinal + "- %s ($%.2f ) \n", damageDesc, damageCost);
//Also could have used the below
//damageDescFinal = (damageDescFinal+"- "+damageDesc+
// " ($"+damageCost+")"+"\n");
//All damage costs added together
damageCostFinal = damageCostFinal + damageCost;
System.out.println();
break;
case 'B':
case 'b':
System.out.print("Enter details of traffic infringement: ");
fineDesc = console.next();
console.nextLine();
System.out.print("Enter traffic fine amount: ");
fineCost = console.nextDouble();
//Set fine description and cost on seperate lines
fineDescFinal = String.format(fineDescFinal + "- %s ($%.2f ) \n", fineDesc, fineCost);
//Also could have used the below
//fineDescFinal = fineDescFinal+"- "+fineDesc+
// " ($"+fineCost+")"+"\n";
//All fine costs added together
fineCostFinal = fineCostFinal + fineCost;
System.out.println();
break;
case 'X':
case 'x':
//Exit the damage and fine menu
System.out.print("Exiting data entry menu..."+"\n");
System.out.println();
break;
default:
//Error handling for invalid input
System.out.print("***ERROR*** Invalid Selection!"+"\n");
System.out.println();
break;
}
} while (menuOption != 'X' && menuOption != 'x');
答案 0 :(得分：1)
也许，您需要使用nextLine（）来阅读整行，而不是next
答案 1 :(得分：0)
通过将Double值更改为字符串然后在输入完成后将它们转换回double来修复此问题。这解决了我遇到的扫描仪问题。这是最终的代码：
do {
System.out.println("Damage Repair / Traffic Infringement Data Entry "+
"Menu");
System.out.println("-------------------------------------------------"+
"---");
System.out.println();
System.out.println("A - Record Damage Repair Details");
System.out.println("B - Record Traffic Infringement Details");
System.out.println("X - Exit");
System.out.println();
System.out.print("Enter your selection (A/B/X):");
menuOption = console.next().charAt(0);
//Switch to allow either upper or lower case menuOption
switch (menuOption) {
case 'A':
case 'a':
System.out.print("Enter description of damage repair: ");
//Clear scanner
console.nextLine();
//Input damage description
damageDesc = console.nextLine();
System.out.print("Enter repair cost: ");
//Input damage cost
damageCost= console.nextLine();
//Convert string fineCost back to a double
//This was input as a String as scanner produces an error
double doubleDamageCost = Double.parseDouble(damageCost);
//Set damage description and cost on seperate lines for each input
damageDescFinal = String.format(damageDescFinal + "- %s ($%.2f ) \n", damageDesc, doubleDamageCost);
//Concatenate all fine costs for a final value
damageCostFinal = damageCostFinal + doubleDamageCost;
System.out.println();
break;
case 'B':
case 'b':
System.out.print("Enter details of traffic infringement: ");
//Clear scanner
console.nextLine();
//Input fine description
fineDesc = console.nextLine();
System.out.print("Enter traffic fine amount: ");
//Input fine cost
fineCost = console.nextLine();
//Convert string fineCost back to a double
//This was input as a String as scanner produces an error
double doubleFineCost = Double.parseDouble(fineCost);
//Set fine description and cost on seperate lines for each input
fineDescFinal = String.format(fineDescFinal + "- %s ($%.2f ) \n", fineDesc, doubleFineCost);
//Concatenate all fine costs for a final value
fineCostFinal = fineCostFinal + doubleFineCost;
System.out.println();
break;
case 'X':
case 'x':
//Exit the damage and fine menu
System.out.print("Exiting data entry menu..."+"\n");
System.out.println();
break;
default:
//Error handling for invalid input
System.out.print("***ERROR*** Invalid Selection!"+"\n");
System.out.println();
break;
}
//Exits menu loop and allow code to continue
} while (menuOption != 'X' && menuOption != 'x');
答案 2 :(得分：0)
为什么不在这种情况下使用.ToLowerCase或.ToUperCase？通过这种方式，您可以获得更清晰的代码
do {
System.out.println("Damage Repair / Traffic Infringement Data Entry "+
"Menu");
System.out.println("-------------------------------------------------"+
"---");
System.out.println();
System.out.println("A - Record Damage Repair Details");
System.out.println("B - Record Traffic Infringement Details");
System.out.println("X - Exit");
System.out.println();
System.out.print("Enter your selection (A/B/X):");
Scanner console = new Scanner(System.in);
menuOption = console.next().toLowerCase().charAt(0);
//Switch to allow either upper or lower case menuOption
switch (menuOption) {
case 'a':
System.out.print("Enter description of damage repair: ");
//Clear scanner
console.nextLine();
//Input damage description
damageDesc = console.nextLine();
System.out.print("Enter repair cost: ");
//Input damage cost
damageCost= console.nextLine();
//Convert string fineCost back to a double
//This was input as a String as scanner produces an error
double doubleDamageCost = Double.parseDouble(damageCost);
//Set damage description and cost on seperate lines for each input
damageDescFinal = String.format(damageDescFinal + "- %s ($%.2f ) \n", damageDesc, doubleDamageCost);
//Concatenate all fine costs for a final value
damageCostFinal = damageCostFinal + doubleDamageCost;
System.out.println();
break;
case 'b':
System.out.print("Enter details of traffic infringement: ");
//Clear scanner
console.nextLine();
//Input fine description
fineDesc = console.nextLine();
System.out.print("Enter traffic fine amount: ");
//Input fine cost
fineCost = console.nextLine();
//Convert string fineCost back to a double
//This was input as a String as scanner produces an error
double doubleFineCost = Double.parseDouble(fineCost);
//Set fine description and cost on seperate lines for each input
fineDescFinal = String.format(fineDescFinal + "- %s ($%.2f ) \n", fineDesc, doubleFineCost);
//Concatenate all fine costs for a final value
fineCostFinal = fineCostFinal + doubleFineCost;
System.out.println();
break;
case 'x':
//Exit the damage and fine menu
System.out.print("Exiting data entry menu..."+"\n");
System.out.println();
break;
default:
//Error handling for invalid input
System.out.print("***ERROR*** Invalid Selection!"+"\n");
System.out.println();
break;
}
//Exits menu loop and allow code to continue
} while (menuOption != 'x');
但你应该做更多的课程，比如
Public void menu(){
System.out.println("Damage Repair / Traffic Infringement Data Entry "+
"Menu");
System.out.println("-------------------------------------------------"+
"---");
System.out.println();
System.out.println("A - Record Damage Repair Details");
System.out.println("B - Record Traffic Infringement Details");
System.out.println("X - Exit");
System.out.println();
System.out.print("Enter your selection (A/B/X):");
}
等等，以获得更有条理和更干净的代码。 segementation是你最好的朋友。