我正在开发一个程序,该程序将为用户提供一个菜单,允许他们选择一个选项,然后根据菜单选择要求不同的数字进行计算。我已经开始了这个程序的基本概述,但是我需要帮助获得循环的实现和工作。Java - 菜单循环和数学计算
这里是我到目前为止的代码:
import java.util.Scanner;
public class LB04Alexander {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.println("This program will perform several types of calculations.");
System.out.println();
System.out.println("-MENU-");
System.out.println("Select from the following menu options:");
System.out.println("1 - Compute integer powers of a number");
System.out.println("2 - Compute a factorial");
System.out.println("3 - Compute a square root");
System.out.println("4 - Compute a cube root");
System.out.println("5 - Compute an exponential");
System.out.println("6 - Compute the sine of an angle");
System.out.println("7 - Compute the cosine of an angle");
System.out.println("8 - Convert a positive integer to binary");
System.out.println("9 - Exit");
System.out.println("Please enter the number corresponding to your choice:");
int menuChoice = input.nextInt();
while (menuChoice >= 1 && menuChoice <= 9); {
switch (menuChoice) {
case 1:
System.out.println("You have chosen to compute integer powers of a number.");
System.out.println("Please enter any number for the base:");
double base1 = input.nextDouble();
System.out.println("Now, enter a non-negative integer for the exponent:");
int exponent1 = input.nextInt();
if (exponent1 < 0)
System.out.println("Error: exponent is negitive.");
else
System.out.println(base1 + "^" + exponent1 + " = " + "");
break;
case 2:
System.out.println("You have chosen to compute a factorial (n!) of a non-negative integer.");
System.out.println("Please enter a non-negitive integer for n:");
long fact = input.nextLong();
int result = 1;
if (fact < 0)
System.out.println("Error: integer is negitive.");
else if (fact >= 127)
System.out.println("Error: Answer too large to calculate");
else
for (int i = 1; i <= fact; i++) {
result = result * i;
}
System.out.println(fact + "! = " + result);
break;
case 3:
System.out.println("You have chosen to compute a square root.");
break;
case 4:
System.out.println("You have chosen to compute a cube root.");
break;
case 5:
System.out.println("You have chosen to compute an exponential.");
break;
case 6:
System.out.println("You have chosen to compute the sine of an angle.");
break;
case 7:
System.out.println("You have chosen to compute the cosine of an angle.");
break;
case 8:
System.out.println("You have chosen to convert a positive integer to binary");
break;
case 9:
System.out.println("You have chosen to exit");
System.out.println("Program LB04Alexander is now terminating...");
input.close();
System.out.println("The program has ended. Goodbye.");
break;
default:
System.out.println("Invalid menu choice, please try again.");
break;
} }
}
}
我有越来越菜单循环正道的第一个问题。它要么不工作,要么永远循环。
目前,该程序接受许多,但什么都不做。如果我通过'while(menuChoice> = 1 && menuChoice <= 9)将while循环更改为do-while,'最后,如果有效,但会一遍又一遍地循环选择的案例。 – Gregory