有人可以帮我弄清楚索引应该是什么来让它完全运行我已经尝试了各种修复，没有任何工作正常。我觉得这个问题出现在data的第一个声明中
String[][] data = new String[MAXPASSENGERS][6];
第一个错误在这里：
int status = Integer.parseInt(data[i][1]);
线程中的异常＆＃34; main＆＃34; java.lang.ArrayIndexOutOfBoundsException：1` 在Titanic.getTotalNumberofPerishedPassengers（Titanic.java:43）1
第二个错误在这里：
int status = Integer.parseInt(data[i][1]);
在这里
return getTotalPassengers() - getTotalNumberofPerishedPassengers();
有这些错误
线程中的异常＆＃34; main＆＃34; java.lang.ArrayIndexOutOfBoundsException：1 在Titanic.getTotalNumberofPerishedPassengers（Titanic.java:43）
和
return getTotalPassengers() - getTotalNumberofPerishedPassengers();
第三个错误：
int status = Integer.parseInt(data[i][1]);
线程中的异常＆＃34; main＆＃34; java.lang.ArrayIndexOutOfBoundsException：1，at TItanic.getTotalNumberofSurvivedPassengerByClass（Titanic.java:71）
如何解决这些问题以使我的代码正常运行？我尝试过更改数组值，但是没有做任何事情，我得到了同样的错误结果。
/**
* file：TestTitanic.java作者：日期：8月15日 * / import java.util.Scanner;
/ * TestTitanic用于测试泰坦尼克号数据 * / 公共课TestTitanic {
public static void main(String[] args) {
String fileName = "";
Titanic titanic = null;
//Get the file name from command line arguments
if (args.length > 0) {
fileName = args[0];
} else {
fileName = "titaniiiic.txt";
}
// Check the file and create titanic statistics
try {
titanic = new Titanic(fileName);
} catch (Exception ex) {
System.out.println("File not found");
System.exit(1);
}
//The application should keep track of the elapsed time (in seconds)
long startTime = System.currentTimeMillis();
//A user-friendly and well-organized menu s
String choices[] = {"Total number of passengers on the Titanic",
"Total number of passengers who perished on the Titanic",
"Total number of Passengers who survived the sinking of the Titanic",
"Number of passengers who survived the sinking of the Titanic as a function of the passenger class (e.g. 1,2,3)",
"Number of passengers who survived the sinking of the Titanic as a function of the passenger gender (e.g., male, female)",
"A list of the names of passengers who paid greater than $200 for their tickets",
"A list of the names of passengers who were less than 10 years old who survived",
"A list of the names of passengers who were less than 10 years old who perished ",
"The count of the number of passengers as a function of the first letter of their last name. (e.g., A: 13, B:33 …)", "Exit"
};
int choice = menuChoice(choices);
while (choice != 10) {
switch (choice) {
case 1:
System.out.println("Total number of passengers on the Titanic: " + titanic.getTotalPassengers());
break;
case 2:
System.out.println("Total number of passengers who perished on the Titanic: " + titanic.getTotalNumberofPerishedPassengers());
break;
case 3:
System.out.println("Total number of passengers who survived : " + titanic.getTotalNumberofSurvivedPassengers());
break;
case 4:
System.out.print("Enter class (e.g. 1,2,3): ");
int cls = getIntInRange(1, 3);
System.out.println(cls + " class number of passengers who survived: " + titanic.getTotalNumberofSurvivedPassengersByClass(cls));
break;
case 5:
System.out.print("Names of passengers who were less than 10 years old who survived: ");
System.out.println(titanic.getSurvivedNamesLessGivenAge(10));
break;
case 6:
System.out.print("Enter the letter: ");
char ch = getString().charAt(0);
System.out.println("Count: " + titanic.getCountByFirstLetterOfFirstName(ch));
break;
}
choice = menuChoice(choices);
}
//The application should keep track of the elapsed time (in seconds)
long endTime = System.currentTimeMillis();
long elapsedTime = (endTime - startTime) / 1000;
/**
* After the program is exited, the application should provide a prompt
* thanking the user for trying the Titanic program and providing the
* total time elapsed.
*/
System.out.println("Thank you for trying the Titanic program");
System.out.println("Elapsed time: " + elapsedTime);
}
/**
* Helper method to get String from user
*
* @return
*/
public static String getString() {
Scanner input = new Scanner(System.in);
return input.nextLine();
}
/**
* Helper method to get user input in range
*
* @param low
* @param high
* @return
*/
public static int getIntInRange(int low, int high) {
int num = 0;
do {
num = getInt();
if (num < low || num > high) {
System.out.println("Enter number between " + low + " and " + high);
}
} while (num < low || num > high);
return num;
}
/**
*
* method to display organized menu to user
*
* @param choices
* @return
*/
public static int menuChoice(String choices[]) {
int choice = 0;
System.out.println("");
for (int i = 0; i < choices.length; i++) {
System.out.println((i + 1) + ". " + choices[i]);
}
System.out.print("Enter choice (1-" + choices.length + "): ");
choice = getIntInRange(1, choices.length);
return choice;
}
/**
* Helper method to get int from user
*
* @return
*/
public static int getInt() {
Scanner input = new Scanner(System.in);
int num = -1;
boolean good;
do {
good = true;
try {
num = input.nextInt();
} catch (Exception e) {
good = false;
input = new Scanner(System.in);
System.out.println("Enter numeric value: ");
}
} while (!good);
return num;
}
}
import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;
// java class Titanic
public class Titanic {
int MAXPASSENGERS = 10000;
int actualPassengers = 0;
//B. Use a 2D array to store the Titanic data.
String[][] data = new String[MAXPASSENGERS][6];
/**
* Constructor to read file and set 2D array to store the Titanic data
*/
Titanic(String filename) throws FileNotFoundException {
Scanner fileReader = new Scanner(new File(filename));
while (fileReader.hasNextLine()) {
//line has tab delimeted data
data[actualPassengers++] = fileReader.nextLine().split("\t");
}
fileReader.close();
}
/**
*
* @return Total number of passengers on the Titanic
*/
public int getTotalPassengers() {
return actualPassengers;
}
/**
*
* @return Total number of passengers who perished on the Titanic
*/
public int getTotalNumberofPerishedPassengers() {
int count = 0;
for (int i = 0; i < getTotalPassengers(); i++) {
int status = Integer.parseInt(data[i][1]);
//Survived (1=yes, 0=no)
if (status == 0) {
count++;
}
}
return count;
}
/**
*
* @return Total number of Passengers who survived the sinking of the
* Titanic
*/
public int getTotalNumberofSurvivedPassengers() {
return getTotalPassengers() - getTotalNumberofPerishedPassengers();
}
/**
* Number of passengers who survived the sinking of the Titanic as a
* function of the passenger class (e.g. 1,2,3)
*
* @param cls
* @return
*/
public int getTotalNumberofSurvivedPassengersByClass(int cls) {
int count = 0;
for (int i = 0; i < getTotalPassengers(); i++) {
int status = Integer.parseInt(data[i][1]);
int clazz = Integer.parseInt(data[i][0]);
//Survived (1=yes, 0=no)
if (status == 1 && clazz == cls) {
count++;
}
}
return count;
}
/**
* Number of passengers who survived the sinking of the Titanic as a
* function of the passenger gender (e.g., male, female)
*
* @param cls
* @return
*/
public int getTotalNumberofSurvivedPassengersByGender(String gender) {
int count = 0;
for (int i = 0; i < getTotalPassengers(); i++) {
int status = Integer.parseInt(data[i][1]);
//Survived (1=yes, 0=no)
if (status == 1 && gender.equalsIgnoreCase(data[i][3])) {
count++;
}
}
return count;
}
/**
*
* @param cls
* @return A list of the names of passengers who paid greater than given
* fair for their tickets
*/
public String getNamesPaidFare(double fair) {
String name = "";
for (int i = 0; i < getTotalPassengers(); i++) {
if (data[i].length >= 6) {
double pfair = Double.parseDouble(data[i][5]);
if (pfair > fair) {
name += "\n" + data[i][2];
}
}
}
return name;
}
/**
* G. A list of the names of passengers who were less than 10 years old who
* survived the sinking of the Titanic
*
* @param fair
* @return
*/
public String getSurvivedNamesLessGivenAge(int age) {
String name = "";
for (int i = 0; i < getTotalPassengers(); i++) {
if (data[i].length >= 6 && data[i][4].length()>0) {
int status = Integer.parseInt(data[i][1]);
double pAge = Double.parseDouble(data[i][4]);
//Survived (1=yes, 0=no)
if (status == 1 && pAge < age) {
name += "\n" + data[i][2];
}
}
}
return name;
}
/**
* H. A list of the names of passengers who were less than 10 years old who
* perished on the Titanic
*
* @param fair
* @return
*/
public String getPerishedNamesLessGivenAge(int age) {
String name = "";
for (int i = 0; i < getTotalPassengers(); i++) {
if (data[i].length >= 6 && data[i][4].length()>0) {
int status = Integer.parseInt(data[i][1]);
double pAge = Double.parseDouble(data[i][4]);
//Survived (1=yes, 0=no)
if (status ==0 && pAge < age) {
name += "\n" + data[i][2];
}
}
}
return name;
}
/**
* The count of the number of passengers as a function of the first letter
* of their last name. (e.g., A: 13, B:33 …)
*
* @param ch
* @return
*/
public int getCountByFirstLetterOfFirstName(char ch) {
int count = 0;
for (int i = 0; i < getTotalPassengers(); i++) {
char pChar = data[i][2].charAt(0);
if (Character.toUpperCase(ch) == Character.toUpperCase(pChar)) {
count++;
}
}
return count;
}
}
答案 0 :(得分：0)
所以我想出了对ArrayIndexOutOfBounds错误的修复并使其工作。上述课程唯一剩下的问题是回答问题4（按班级幸存者）。这是Titanic.java类的那部分代码的代码：
/**
* Number of passengers who survived the sinking of the Titanic as a
* function of the passenger class (e.g. 1,2,3)
*
* @param cls
* @return
*/
public int getTotalNumberofSurvivedPassengersByClass(int cls) {
int count = 0;
for (int i = 0; i < getTotalPassengers(); i++) {
int status = Integer.parseInt(data[i][1]);
int clazz = Integer.parseInt(data[i][0]);
//Survived (1 = yes, 0 = no)
if (status == 1 && clazz == cls) {
count++;
}
}
return count;