Question

我一直在为我为作业创建的这种方法而苦苦挣扎，这让我疯狂。我的if / else语句有问题，但我似乎无法找出它是什么。这是我收到的输出：

1: Lather and Rise.
2: Lather and rinse.
Done
2: Lather and Rise.
2: Lather and rinse.
Done
3: Lather and Rise.
2: Lather and rinse.
Done

我希望看到这个：

1: Lather and rinse.
2: Lather and rinse.
Done.

如果不能正确输出，我做错了什么？任何建议/帮助表示赞赏！请参阅下面的代码：

public class ShampooMethod {

    public static void printShampooInstructions(int numCycles) {

        for (int i = 1; i < 4; i++) {
            System.out.println(i + ": Lather and Rise.");
            if (numCycles < 1) {
                System.out.println("Too few.");
            } else if (numCycles >= 4) {
                System.out.println("Too many");
            } else {
                System.out.println(numCycles + ": Lather and rinse.");
            }
            System.out.println("Done");
        }
    }


    public static void main(String[] args) {
        printShampooInstructions(2);

        return;
    }
}

Answer 1

查看下面的评论，看看是什么导致了与预期不同的输出。

您正在迭代一次
System.out.println(i + ": Lather and Rise.");将在循环的每一轮中显示，因为您没有使用if或else或else if 过滤它
循环后System.out.println("Done");的切换位置 - 因为如果循环完成并且您处于方法的末尾就完成了。

public class ShampooMethod {

    public static void printShampooInstructions(int numCycles) {

        // i = 1 - i < (2+1=3) -> i will become 1 and than 2 -> done
        for (int i = 1; i < (numCycles+1); i++) {
            // this would be displayed every time you go throw the loop
            // System.out.println(i + ": Lather and Rise.");
            if (numCycles < 1) {
                System.out.println("Too few.");
            } else if (numCycles >= 4) {
                System.out.println("Too many");
            } else {
                System.out.println(i + ": Lather and rinse.");
            }
        }
        // Done goes here because only after the loop we are done
        System.out.println("Done");
    }


    public static void main(String[] args) {
        printShampooInstructions(2);

        return;
    }
}

Answer 2

循环中的所有内容都会执行循环运行的次数。在这种情况下，循环执行3次，因为这是你设置的（int i = 1; i＆lt; 4; i ++）。线条＆＃34; Lather and Rise＆＃34;和＆＃34;完成＆＃34;多次打印，因为它们也在该循环内。此外，您没有设置Sentinal以防止最后两个＆＃34; 2：泡沫和冲洗。＆＃34;从打印。如果您不打印任何内容，请设置一个案例。

Answer 3

线路：每次循环运行时都会输出'Lather and Rise'，因为它不在if / else块内。与'完成'相同的事情。将此行放在for循环之外。另外要指出的是，而不是硬编码4，将i＆lt; numCycles。因此，在您要显示2个“Lather and rinse”循环的情况下，numCycles应为2.

public static void printShampooInstructions(int numCycles) {

    for (int i = 0; i < numCycles; i++) {
        // System.out.println(i + ": Lather and Rise.");
        if (numCycles < 1) {
            System.out.println("Too few.");
        } else if (numCycles >= 4) {
            System.out.println("Too many");
        } else {
            System.out.println(numCycles + ": Lather and rinse.");
        }   
    }
    System.out.println("Done");
}

Answer 4

    if (numCycles < 1) {
       System.out.println("Too few.");
      }
    else if (numCycles > 4) {
       System.out.println("Too many.");
      }
    else {
       for (i = 1; i <= numCycles; ++i) {
          System.out.println(i + ": Lather and rinse.");
         }
        System.out.println("Done.");
      }

我使用了 if else 语句，并在 else 实例的语句尾部，创建了一个 for for循环，它将打印 Lather and Rinse 声明随后完成并且有效。

Answer 5

6.4.2：带有循环的方法：洗发水。

编写一个方法printShampooInstructions（），其参数为int numCycles，返回类型为void。如果numCycles小于1，则打印“太少”。如果大于4，则打印“太多”。否则，打印“ N：起泡并冲洗”。 numCycles次，其中N是循环数，后跟“完成”。以换行符结尾。输入2的示例输出：

1：起泡并冲洗。

2：起泡并冲洗。

完成。

import java.util.Scanner;

public class ShampooMethod {

   /* Your solution goes here  */
   public static void printShampooInstructions(int numCycles) {
      if (numCycles < 1){
      System.out.println("Too few.");   
      }
      else if (numCycles > 4){
      System.out.println("Too many.");
      } 
      else {
         for(int i = 1; i <= numCycles; i++){
            System.out.println(i + ": Lather and rinse.");
         }
         System.out.println("Done.");
      }
   }

   public static void main (String [] args) {
      Scanner scnr = new Scanner(System.in);
      int userCycles;

      userCycles = scnr.nextInt();
      printShampooInstructions(userCycles);
   }
}

Answer 6

    import java.util.Scanner;
    public class Methods_ShampooMethod_ChallengeActivity {

        public static void printShampooInstructions(int numCycles) {
            

            if (numCycles < 1) {
                System.out.println("Too few.");
            }
            else if (numCycles > 4) {
                System.out.println("Too many.");
            }
            else {
                for (int i = 1; i <= numCycles; i++) {
                    System.out.println(i + ": Lather and rinse.");         
                }
            System.out.println("Done.");           
            }                
        }

        public static void main (String [] args) {
            Scanner scnr = new Scanner(System.in);
            int userCycles;
        
            System.out.print("Enter cycles: ");
            userCycles = scnr.nextInt();
        
            printShampooInstructions(userCycles);   
        }
    }

Answer 7

公共类洗发方法{

public static void printShampooInstructions(int numCycles) {
    if (numCycles < 1) {
        System.out.println("Too few.");
    } else if (numCycles > 4) {
        System.out.println("Too many.");
    } else {
        for (int i = 1; i <= numCycles; i++) {
            System.out.println(i + ": Lather and rinse.");
        }
        System.out.println("Done.");
    }
}

public static void main(String[] args) {
    Scanner scnr = new Scanner(System.in);
    int userCycles;

    userCycles = scnr.nextInt();
    printShampooInstructions(userCycles);
}

}

Answer 8

在第一个 for 循环中输入： for (int i = 1; i < numCycles; i++) 而不是这个： for (int i = 1; i < 4; i++)

代码中循环的输出不正确

8 个答案: