由於一些其他的答案說,你可以使用boolean
檢查的情況下已使用與否。但是,您也可以使用int
。使用int
的優點是您可以指定每個案例可以使用多少次。例如,以下代碼只能使用每個案例一次。
import java.util.Scanner;
public class Test {
public static void main(String[] args) {
Scanner user_input = new Scanner(System.in);
int choice;
int case1 = 0, case2 = 0, case3 = 0;
int case1lim = 1, case2lim = 1, case3lim = 1;
System.out.println("You may use may enter the number 1 " + case1lim + " times");
System.out.println("You may use may enter the number 2 " + case2lim + " times");
System.out.println("You may use may enter the number 3 " + case3lim + " times");
do {
System.out.println("Please enter a number between 1 and 3");
choice = user_input.nextInt();
if(choice == 1 && case1 < case1lim || choice == 2 && case2 < case2lim || choice == 3 && case3 < case3lim) {
switch(choice){
case 1: //print something;
case1++;
break;
case 2: //print something;
case2++;
break;
case 3: //print something;
case3++;
break;
default: //print default;
break;
}
} else {
System.out.println("Please pick another number since you have already used that case or you entered a bad value");
}
} while(true);
}
}
但是如果你改變了行
int case1lim = 1, case2lim = 1, case3lim = 1;
的值
int case1lim = 2, case2lim = 1, case3lim = 1;
你可以使用兩次第一種情況下,所有的其他情況下一次。
來源
2016-01-23 10:19:35
Dan
這是'Java'還是'C#'或'Any'? – Ian