我有一个方法,它使用switch
语句为用户提供要选择的选项,一旦用户选择了一个选项并且执行了case
中的代码,我如何返回到提供另一个菜单的主方法?
我的部分代码:
static void modifyStudent() {
System.out.println("Wish student would you like to change?");
for(int i=0;i<10;i++){
System.out.println(i + ": " + studentNamesArray[i]);
}
int studentChoice = input.nextInt();
System.out.println("1: Change name.");
....
int detailChange = input.nextInt();
switch (detailChange) {
case 1:
String newName = input.next();
studentNamesArray[studentChoice] = newName;
break;
....
}
public static void main(String[] args) {
while (1 == 1) {
System.out.println("Please select an option:");
System.out.println("1: Add a student.");
....
int choice = input.nextInt();
switch (choice) {
case 1:
....
}
编辑(要求完整代码):
/**
* User: Colin Shewell
* Date: 26/11/13
* Time: 10:32
*/
import java.util.Scanner;
import java.util.Arrays; //REMOVE THIS!!!
public class StudentMarks {
static Scanner input = new Scanner(System.in);
static String[] studentNamesArray = new String[10];
static int[][] studentMarksArray = new int[10][3];
static int nameArrayCount, markArrayCount = 0;
static int markOne, markTwo, markThree;
static String studentName;
static void printArrays(){
System.out.println(Arrays.toString(studentNamesArray));
for (int index=0;index<10;index++)
{
System.out.println(studentMarksArray[index][0]);
System.out.println(studentMarksArray[index][1]);
System.out.println(studentMarksArray[index][2]);
}
}
static void addStudent() {
if (nameArrayCount < 10) {
System.out.println("Enter the student's name in the following format - surname, forename: ");
studentName = input.next();
studentNamesArray[nameArrayCount] = studentName;
nameArrayCount = nameArrayCount + 1;
}
else if (nameArrayCount == 10) {
System.out.println("******Array is full, please delete a student before adding another.*****");
}
if (markArrayCount < 10){
System.out.println("Enter the first mark: ");
markOne = input.nextInt();
System.out.println("Enter the second mark: ");
markTwo = input.nextInt();
System.out.println("Enter the third mark: ");
markThree = input.nextInt();
studentMarksArray[markArrayCount][0] = markOne;
studentMarksArray[markArrayCount][1] = markTwo;
studentMarksArray[markArrayCount][2] = markThree;
markArrayCount = markArrayCount + 1;
}
}
static void modifyStudent() {
System.out.println("Wish student would you like to change?");
for(int i=0;i<10;i++){
System.out.println(i + ": " + studentNamesArray[i]);
}
int studentChoice = input.nextInt();
System.out.println("1: Change name.");
System.out.println("2: Change first mark.");
System.out.println("3: Change second mark.");
System.out.println("4: Change third mark.");
System.out.println("5: Change all marks.");
int detailChange = input.nextInt();
switch (detailChange) {
case 1:
System.out.println("Enter the new student name.");
String newName = input.next();
studentNamesArray[studentChoice] = newName;
return;
case 2:
System.out.println("Enter the new mark for mark one.");
int newMarkOne = input.nextInt();
studentMarksArray[studentChoice][0] = newMarkOne;
return;
case 3:
//two
break;
case 4:
//three
break;
case 5:
//all
break;
default:
System.exit(0);
break;
}
}
public static void main(String[] args) {
while (true) {
System.out.println("Please select an option:");
System.out.println("1: Add a student.");
System.out.println("2: Modify the details of an existing student.");
System.out.println("3: Delete an existing student.");
System.out.println("4: Sort in alphabetical order by name.");
System.out.println("5: Output the student name and corresponding marks in ascending name order.");
System.out.println("6: Output the student name and corresponding marks in descending name order.");
System.out.println("7: Display the student with the highest average mark.");
System.out.println("8: Display the student with the lowest average mark.");
System.out.println("9: Display the average score of all students recorded.");
System.out.println("10: Exit.");
int choice = input.nextInt();
switch (choice) {
case 1:
addStudent();
System.out.println(Arrays.toString(studentNamesArray));
break;
case 2:
modifyStudent();
break;
case 3:
printArrays();
break;
/* case 4:
sortAlphabetical();
break;
case 5:
outputNameMarksAsc();
break;
case 6:
outputNameMarksDsc();
break;
case 7:
highestStudentAvgMark();
break;
case 8:
lowestStudentAvgMark();
break;
case 9:
displayAvgScore();
break; */
case 10:
System.exit(0);
break;
default:
System.exit(0);
break;
}
}
}
}
只需return
到主方法。return
只是退出该方法,并从调用它的行继续执行代码。
case 1:
String newName = input.next();
studentNamesArray[studentChoice] = newName;
return; //exits this method
//break; <-- not needed after a return!
您的代码将在无限循环中运行,您可以使用类似的条件标志来运行它
boolean isRunning = true;
while (isRunning) {
System.out.println("Please select an option:");
System.out.println("1: Add a student.");
....
int choice = input.nextInt();
switch (choice) {
case 1:
isRunning = false;
//your code for case 1
....
}
//rest of the code in main executes now
这将退出while循环,返回主方法