在Java代码中,在完成菜单中的一个选项后,需要知道如何返回主菜单吗?
我正在研究Java代码。我有一个菜单,用户选择一个选项,在该选项中执行某些操作,然后返回菜单,直到选择退出。我不知道如何让它回到菜单上 以下是我所拥有的:在Java代码中,在完成菜单中的一个选项后,需要知道如何返回主菜单吗?,java,menu,Java,Menu,我正在研究Java代码。我有一个菜单,用户选择一个选项,在该选项中执行某些操作,然后返回菜单,直到选择退出。我不知道如何让它回到菜单上 以下是我所拥有的: /** * * @author Lisa Hergert */ import java.util.Scanner; import java.util.Random; public class MathTutor { //Create scanner for user input Scanner keyboard =
/**
*
* @author Lisa Hergert
*/
import java.util.Scanner;
import java.util.Random;
public class MathTutor {
//Create scanner for user input
Scanner keyboard = new Scanner(System.in);
//Declare variables
int choice;
Random generator = new Random();
public MathTutor () {
choice = 0;
}
public int getQuestionType() {
while (choice < 1 || choice >3) {
System.out.println("Math Tutor");
System.out.println("\t1) Addition problem");
System.out.println("\t2) Subtraction problem");
System.out.println("\t3) Quit");
System.out.println("Enter your choice (1 - 3): ");
choice = keyboard.nextInt();
if (choice < 1 || choice > 3) {
System.out.println("You must choose a number from 1-3");
}
}
return choice;
}
public void askQuestions () {
for (int i = 0; i < 4; i++) {
int num1 = genRandomNum();
int num2 = genRandomNum();
int max = choice;
if (max == 3) {
max = (int)(Math.random() * 3 + 1);
}
switch (max) {
case 1: addition(num1, num2);
break;
case 2: subtraction(num1, num2);
break;
default: System.out.println("Error");
System.exit(1);
}
}
}
public int genRandomNum() {
return (int)generator.nextInt(1000);
}
public void addition(int num1, int num2) {
if (num1 > num2) {
System.out.printf("%5d\n", num1);
System.out.printf("+ %3d\n", num2);
System.out.println("-------");
} else {
System.out.printf("%5d\n", num2);
System.out.printf("+ %3d\n", num1);
System.out.println("-------");
}
int sum = num1 + num2;
int answer = keyboard.nextInt();
if (num1 + num2 == answer) {
System.out.println("Good job, you got it right!");
} else {
System.out.println("Good try, the correct answer is: " + sum);
}
}
public void subtraction (int num1, int num2) {
if (num1 > num2) {
System.out.printf("%5d\n", num1);
System.out.printf("- %3d\n", num2);
System.out.println("-------");
int diff = num1 - num2;
int answer = keyboard.nextInt();
if (num1 - num2 == answer) {
System.out.println("Good job, you got it right!");
} else {
System.out.println("Good try, the correct answer is: " + diff);
}
} else {
System.out.printf("%5d\n", num2);
System.out.printf("- %3d\n", num1);
System.out.println("-------");
int diff = num2 - num1;
int answer = keyboard.nextInt();
if (num2 - num1 == answer) {
System.out.println("Good job, you got it right!");
} else {
System.out.println("Good try, the correct answer is: " + diff);
}
}
}
public static void main(String[] args) {
MathTutor tutor = new MathTutor();
int choice = tutor.getQuestionType();
tutor.askQuestions();
return;
}
}
/**
*
*@作者丽莎·赫格特
*/
导入java.util.Scanner;
导入java.util.Random;
公开课数学导师{
//为用户输入创建扫描仪
扫描仪键盘=新扫描仪(System.in);
//声明变量
智力选择;
随机生成器=新随机();
公共数学导师(){
选择=0;
}
public int getQuestionType(){
而(选项<1 | |选项>3){
System.out.println(“数学导师”);
System.out.println(“\t1)加法问题”);
System.out.println(“\t2)减法问题”);
System.out.println(“\t3)Quit”);
System.out.println(“输入您的选择(1-3):”;
choice=keyboard.nextInt();
如果(选项<1 | |选项>3){
System.out.println(“您必须从1-3中选择一个数字”);
}
}
回报选择;
}
公开提问(){
对于(int i=0;i<4;i++){
int num1=genRandomNum();
int num2=genRandomNum();
int max=选择;
如果(最大==3){
max=(int)(Math.random()*3+1);
}
开关(最大值){
案例1:添加(num1,num2);
打破
情况2:减法(num1,num2);
打破
默认值:System.out.println(“错误”);
系统出口(1);
}
}
}
public int genRandomNum(){
返回(int)生成器。nextInt(1000);
}
公共无效添加(整数num1,整数num2){
如果(num1>num2){
System.out.printf(“%5d\n”,num1);
System.out.printf(“+%3d\n”,num2);
System.out.println(“----”);
}否则{
System.out.printf(“%5d\n”,num2);
System.out.printf(“+%3d\n”,num1);
System.out.println(“----”);
}
整数和=num1+num2;
int answer=keyboard.nextInt();
如果(num1+num2==答案){
System.out.println(“干得好,你做对了!”);
}否则{
System.out.println(“很好的尝试,正确的答案是:“+sum”);
}
}
公共无效减法(整数num1,整数num2){
如果(num1>num2){
System.out.printf(“%5d\n”,num1);
System.out.printf(“-%3d\n”,num2);
System.out.println(“----”);
int diff=num1-num2;
int answer=keyboard.nextInt();
如果(num1-num2==答案){
System.out.println(“干得好,你做对了!”);
}否则{
System.out.println(“很好的尝试,正确的答案是:”+diff);
}
}否则{
System.out.printf(“%5d\n”,num2);
System.out.printf(“-%3d\n”,num1);
System.out.println(“----”);
int diff=num2-num1;
int answer=keyboard.nextInt();
如果(num2-num1==答案){
System.out.println(“干得好,你做对了!”);
}否则{
System.out.println(“很好的尝试,正确的答案是:”+diff);
}
}
}
公共静态void main(字符串[]args){
MathTutor=新的MathTutor();
int choice=tutor.getQuestionType();
辅导教师。询问问题();
返回;
}
}
导入java.util.Scanner;
导入java.util.Random;
/**
*
*@作者丽莎·赫格特
*/
公开课数学导师{
//为用户输入创建扫描仪
扫描仪键盘=新扫描仪(System.in);
//声明变量
智力选择;
随机生成器=新随机();
公共数学导师(){
选择=0;
}
public int getQuestionType(){
而(选项<1 | |选项>3){
System.out.println(“数学导师”);
System.out.println(“\t1)加法问题”);
System.out.println(“\t2)减法问题”);
System.out.println(“\t3)Quit”);
System.out.println(“输入您的选择(1-3):”;
choice=keyboard.nextInt();
如果(选项<1 | |选项>3){
System.out.println(“您必须从1-3中选择一个数字”);
}
}
回报选择;
}
公开提问(){
int num1=genRandomNum();
int num2=genRandomNum();
int max=选择;
如果(最大==3){
max=(int)(Math.random()*3+3);
}
开关(最大值){
案例1:添加(num1,num2);
打破
情况2:减法(num1,num2);
打破
默认值:System.out.println(“感谢您抽出时间”);
系统出口(1);
}
}
public int genRandomNum(){
返回(int)生成器。nextInt(1000);
}
公共无效添加(整数num1,整数num2){
如果(num1>num2){
System.out.printf(“%5d\n”,num1);
System.out.printf(“+%3d\n”,num2);
System.out.println(“----”);
}否则{
System.out.printf(“%5d\n”,num2);
System.out.printf(“+%3d\n”,num1);
System.out.println(“----”);
}
整数和=num1+num2;
int answer=keyboard.nextInt();
如果(num1+num2==答案){
System.out.println(“干得好,你做对了!”);
}否则{
System.out.println(“很好的尝试,正确的答案是:“+sum”);
}
数学
import java.util.Scanner;
import java.util.Random;
/**
*
* @author Lisa Hergert
*/
public class MathTutor {
//Create scanner for user input
Scanner keyboard = new Scanner(System.in);
//Declare variables
int choice;
Random generator = new Random();
public MathTutor () {
choice = 0;
}
public int getQuestionType() {
while (choice < 1 || choice >3) {
System.out.println("Math Tutor");
System.out.println("\t1) Addition problem");
System.out.println("\t2) Subtraction problem");
System.out.println("\t3) Quit");
System.out.println("Enter your choice (1 - 3): ");
choice = keyboard.nextInt();
if (choice < 1 || choice > 3) {
System.out.println("You must choose a number from 1-3");
}
}
return choice;
}
public void askQuestions () {
int num1 = genRandomNum();
int num2 = genRandomNum();
int max = choice;
if (max == 3) {
max = (int)(Math.random() * 3+3);
}
switch (max) {
case 1: addition(num1, num2);
break;
case 2: subtraction(num1, num2);
break;
default: System.out.println("Thank you for your time.");
System.exit(1);
}
}
public int genRandomNum() {
return (int)generator.nextInt(1000);
}
public void addition(int num1, int num2) {
if (num1 > num2) {
System.out.printf("%5d\n", num1);
System.out.printf("+ %3d\n", num2);
System.out.println("-------");
} else {
System.out.printf("%5d\n", num2);
System.out.printf("+ %3d\n", num1);
System.out.println("-------");
}
int sum = num1 + num2;
int answer = keyboard.nextInt();
if (num1 + num2 == answer) {
System.out.println("Good job, you got it right!");
} else {
System.out.println("Good try, the correct answer is: " + sum);
}
MathTutor tutor = new MathTutor();
int choice = tutor.getQuestionType();
tutor.askQuestions();
}
public void subtraction (int num1, int num2) {
if (num1 > num2) {
System.out.printf("%5d\n", num1);
System.out.printf("- %3d\n", num2);
System.out.println("-------");
int diff = num1 - num2;
int answer = keyboard.nextInt();
if (num1 - num2 == answer) {
System.out.println("Good job, you got it right!");
} else {
System.out.println("Good try, the correct answer is: " + diff);
}
} else {
System.out.printf("%5d\n", num2);
System.out.printf("- %3d\n", num1);
System.out.println("-------");
int diff = num2 - num1;
int answer = keyboard.nextInt();
if (num2 - num1 == answer) {
System.out.println("Good job, you got it right!");
} else {
System.out.println("Good try, the correct answer is: " + diff);
}
}
MathTutor tutor = new MathTutor();
int choice = tutor.getQuestionType();
tutor.askQuestions();
}
public static void main(String[] args) {
MathTutor tutor = new MathTutor();
int choice = tutor.getQuestionType();
tutor.askQuestions();
}
}
public static void main(String[] args) {
MathTutor tutor = new MathTutor();
int choice = tutor.getQuestionType();
while(choice != 3) {
tutor.askQuestions();
choice = tutor.getQuestionType();
}
return;
}