嗨我已经完成了这个程序它工作正常，除非用户试图用大写字母写我试过.toUpperCase但它仍然关闭程序如果你试图使用大写字母搜索可以任何人帮助，谢谢你
import java.io.*;
import java.util.Scanner;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
public class database
{
static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
//my arrays
static String country [] = new String[1000];
static String capital [] = new String[1000];
static double population [] = new double[1000];
static List<String> countriesList = Arrays.asList (country); //a new array for user to add data to
public static void main (String args [])throws IOException
{
// now i am adding data to the arrays
country[0] = "Barbados";
capital[0] = "Bridgetown";
population[0] = 65.3;
country[1] = "france";
capital[1] = "paris";
population[1] = 315.8;
country[2] = "nigeria";
capital[2] = "abuja";
population[2] = 170.1;
country[3] = "USA";
capital[3] = "washington";
population[3] = 2840;
country[4] = "japan";
capital[4] = "tokoyo";
population[4] = 126.7;
int option = 0;
System.out.println("WELCOME TO MY COUNTRY DATABASE\n");
while(option!= 5){ //Only five options
options();
option = Integer.parseInt(br.readLine());
if(option > 5 || option < 1)
{
System.out.println("Wrong input! Try Again");
System.out.println("CHOOSE FROM 1 - 5 \n ");
}
if(option == 1) {
addCountry();
}
else if(option == 2){
searchCountry(); //Search from an array
}
else if(option == 3){
ListCountry();
}
else if(option == 4){
getFare(); //show fare to travel
}
else if(option == 5) {
System.out.print("\n Thank you and Goodbye ");
}
}
}
public static void options()
{
System.out.println("Main menu");
System.out.println("=========");
System.out.println("1. Add a new country");
System.out.println("2. Search for a country");
System.out.println("3. Show list of countries available");
System.out.println("4. Get fare from London to countries listed");
System.out.println("5. Exit");
System.out.print("\n Choose an option from 1 - 5: ");
}
public static void addCountry()throws IOException
{
System.out.println("\n Adding a country");
System.out.println("===================");
System.out.print("Enter name of country: ");
String countryInput = br.readLine();
System.out.print("Enter Capital: ");
String capitalInput = br.readLine();
System.out.print("Enter population: ");
String populationInput = br.readLine();
int spareSlot = -1;
for (int i = 0; i < country.length; i++) // loop so data can be added to arraylist
{
if(country[i] == null)
{
spareSlot = i;
break;
}
}
country[spareSlot] = countryInput;
capital[spareSlot] = capitalInput;
population[spareSlot] = Double.parseDouble(populationInput);
System.out.println("\n You added the country " + countryInput + ", the capital is " + capitalInput + ", with a population of " + populationInput + "\n" );
//System.out.println("================================================================================================================");
}
public static void searchCountry() throws IOException
{
Scanner in = new Scanner (System.in);//Scanner to obtain input from command window
String output;
int size, i;
System.out.println("\n Searching countries");
System.out.println("========================= \n");
System.out.print("Search a Country: ");
output = br.readLine();
boolean found = false;
//A loop to search from the array
for(i = 0; i < country.length; i++)
if(output.equals(country[i]))
{
found = true;
break;
}
if (found)
System.out.println(output + " is found at index " + i +"\n");
else
System.out.println(output + ": This country is not found, choose option 1 to Add country \n");
if (output == country[0])
{
System.out.println("The capital of "+ output + "is " + capital[1] + " with a population of " + population[3]);
}
if(output == country[1]) {
System.out.println("The capital is" + capital[4]);
}
if(output == country[2]) {
System.out.println("The capital is" + capital[1]);
}
if(output == country[3]) {
System.out.println("The capital is " + capital[2]);
}
if(output == country[4]) {
System.out.println("The capital is " + capital[3]);
}
}
public static void ListCountry()throws IOException
{
for (String c : countriesList)
{
if(c!=null)
System.out.println("\n" + c +"\n"); // to list all countries so far in the array
}
}
public static void getFare()
{
Scanner input = new Scanner (System.in);
String destination;
int fare;
System.out.println("\n Get a fare:");
System.out.println("============== \n");
System.out.print("Select destination by entering number from 1 -5: \n");
System.out.println("1 Caribbean");
System.out.println("2 Europe");
System.out.println("3 Africa");
System.out.println("4 America");
System.out.println("5 Japan");
destination = input.nextLine(); //get destination from user
fare = Integer.parseInt(destination);
switch(fare)
{
case 1: System.out.println("To travel to the Carribbean the fare is from £600 \n");
break;
case 2: System.out.println("To travel to Europe the fare is from £199 \n");
break;
case 3: System.out.println("To travel to Africa the fareis from £500 \n");
break;
case 4: System.out.println("To travel to America the fare is from £290 \n");
break;
case 5: System.out.println("To travel to Japan the fare is from £550 \n");
break;
default: System.out.println("INVALID ACTION START AGAIN \n");
System.out.println("======================================");
}
}
}
答案 0 :(得分：0)
你有一个比较阅读
if(output.equals(country[i]))
如果您希望它不区分大小写，则需要将其更改为
if(output.equalsIgnoreCase(country[i]))
稍后在您的代码中，您有类似于
的行 if (output == country[0])
比较对象标识而不是字符串相等。您希望将所有这些更改为至少正确地比较字符串，并且可能不区分大小写，如上所述。