我试图仅允许用户从给定的输入中进行选择。如果他们为第一个optionGate
选择了“ f”,“ F”,“ c”或“ C”以外的其他东西,则会提示他们再次尝试并循环回到扫描仪。下一个门optionGate2
的情况相同。
门通过阻止用户输入与给定选项不同的输入来实现我想要的功能。当两个布尔值都变为true
并且门通过时,我的问题就来了。由于某些原因,扫描仪仍然会无限循环地要求用户输入。然后,我可以一遍又一遍地在扫描仪中键入任何内容,程序不再运行。
关于发生的事情有任何建议或评论吗?
Scanner in = new Scanner(System.in);
boolean optionGate = false;
boolean optionGate2 = false;
String tempLabel = ""; //initialize to F
String precipLabel = ""; //initialize to in
while(optionGate != true){
System.out.println("Choose the temperature scale (F = Fahrenheit, C = Celsius:)");
String scaleT = in.nextLine();
if("f".equalsIgnoreCase(scaleT)){
tempLabel = "F";
optionGate = true;
}
else if("c".equalsIgnoreCase(scaleT)){
tempLabel = "C";
optionGate = true;
}
else{
System.out.println("Error: not an option. Try again:");
optionGate = false;
}
}
while(optionGate2 != true){
System.out.println("Choose the precipitation scale (i = inches, c = centimeters:)");
String scaleP = in.nextLine();
if("i".equalsIgnoreCase(scaleP)){
precipLabel = "in";
optionGate2 = true;
}
else if("c".equalsIgnoreCase(scaleP)){
precipLabel = "cm";
optionGate2 = true;
}
else{
System.out.println("Error: not an option. Try again:");
optionGate2 = false;
}
}
EDIT:添加上述片段之后的代码。 (很抱歉,明显缺少stackoverflow专有技术。这是我在平台上的第一篇文章。)>
这是我主要方法中的所有代码:String [] month = {"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"}; double [] temperature ={60.9, 62.6, 67.4, 71.5, 77.1, 81.2, 82.4, 82.5, 81.1, 75.3, 68.8, 63.0}; //initialize with Fahrenheit values double [] precipitation ={2.4, 2.4, 3.5, 2.4, 3.7, 7.4, 7.2, 6.3, 5.8, 2.7, 2.3, 2.3}; //initialize with inch values double[] updatedTemperature; updatedTemperature = new double[temperature.length]; double[] updatedPrecipitation; updatedPrecipitation = new double[precipitation.length]; while("f".equalsIgnoreCase(tempLabel)){ for(int i = 0 ; i < temperature.length ; i++) { updatedTemperature[i] = temperature[i]; } if("in".equals(precipLabel)){ for(int i = 0 ; i < precipitation.length ; i++){ updatedPrecipitation[i] = precipitation[i]; } } else if("cm".equals(precipLabel)){ for(int i = 0 ; i < precipitation.length ; i++){ updatedPrecipitation[i] = (precipitation[i] * 2.54); } } } while("c".equalsIgnoreCase(tempLabel)){ for(int i = 0 ; i < temperature.length ; i++) { updatedTemperature[i] = ((temperature[i] - 32) * (5.0/9)); } if("in".equals(precipLabel)){ for(int i = 0 ; i < precipitation.length ; i++){ updatedPrecipitation[i] = precipitation[i]; } } else if("cm".equals(precipLabel)){ for(int i = 0 ; i < precipitation.length ; i++){ updatedPrecipitation[i] = (precipitation[i] * 2.54); } } } //Processing - calculate average temperature and total precipitation for( int index = 0; index < updatedTemperature.length; index++) { sum += updatedTemperature[index]; } avg = sum/updatedTemperature.length;
EDIT:
//Declare and initialize variables
Scanner in = new Scanner(System.in);
String city = "Orlando";
String state = "FL";
double sum = 0;
double avg = 0;
boolean optionGate = false;
boolean optionGate2 = false;
String tempLabel = ""; //initialize to F
String precipLabel = ""; //initialize to in
while(optionGate != true){
System.out.println("Choose the temperature scale (F = Fahrenheit, C = Celsius:)");
String scaleT = in.nextLine();
if("f".equalsIgnoreCase(scaleT)){
tempLabel = "F";
optionGate = true;
}
else if("c".equalsIgnoreCase(scaleT)){
tempLabel = "C";
optionGate = true;
}
else{
System.out.println("Error: not an option. Try again:");
optionGate = false;
}
}
while(optionGate2 != true){
System.out.println("Choose the precipitation scale (i = inches, c = centimeters:)");
String scaleP = in.nextLine();
if("i".equalsIgnoreCase(scaleP)){
precipLabel = "in";
optionGate2 = true;
}
else if("c".equalsIgnoreCase(scaleP)){
precipLabel = "cm";
optionGate2 = true;
in.close();
}
else{
System.out.println("Error: not an option. Try again:");
optionGate2 = false;
}
}
String [] month = {"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
double [] temperature ={60.9, 62.6, 67.4, 71.5, 77.1, 81.2, 82.4, 82.5, 81.1, 75.3, 68.8, 63.0}; //initialize with Fahrenheit values
double [] precipitation ={2.4, 2.4, 3.5, 2.4, 3.7, 7.4, 7.2, 6.3, 5.8, 2.7, 2.3, 2.3}; //initialize with inch values
double[] updatedTemperature;
updatedTemperature = new double[temperature.length];
double[] updatedPrecipitation;
updatedPrecipitation = new double[precipitation.length];
while("f".equalsIgnoreCase(tempLabel)){
for(int i = 0 ; i < temperature.length ; i++) {
updatedTemperature[i] = temperature[i];
}
if("in".equals(precipLabel)){
for(int i = 0 ; i < precipitation.length ; i++){
updatedPrecipitation[i] = precipitation[i];
}
}
else if("cm".equals(precipLabel)){
for(int i = 0 ; i < precipitation.length ; i++){
updatedPrecipitation[i] = (precipitation[i] * 2.54);
}
}
}
while("c".equalsIgnoreCase(tempLabel)){
for(int i = 0 ; i < temperature.length ; i++) {
updatedTemperature[i] = ((temperature[i] - 32) * (5.0/9));
}
if("in".equals(precipLabel)){
for(int i = 0 ; i < precipitation.length ; i++){
updatedPrecipitation[i] = precipitation[i];
}
}
else if("cm".equals(precipLabel)){
for(int i = 0 ; i < precipitation.length ; i++){
updatedPrecipitation[i] = (precipitation[i] * 2.54);
}
}
}
//Processing - calculate average temperature and total precipitation
for( int index = 0; index < updatedTemperature.length; index++)
{
sum += updatedTemperature[index];
}
avg = sum/updatedTemperature.length;
//Output: display table of weather data including average and total
System.out.println();
System.out.println(" Weather Data");
System.out.println(" Location: " + city +", " + state);
System.out.println("Month Temperature (" + tempLabel + ") Precipitation (" + precipLabel + ")");
System.out.println();
System.out.println("***************************************************");
for( int index = 0; index < temperature.length; index++)
{
System.out.println(month[index] + "\t " + updatedTemperature[index] + "\t\t " + updatedPrecipitation[index]);
}
System.out.println("***************************************************");
System.out.println("Average: " + avg + " Total: " + sum);
我试图仅允许用户从给定的输入中进行选择。如果他们为第一个optionGate选择了“ f”,“ F”,“ c”或“ C”以外的其他东西,则会提示他们再试一次,然后...