Question

//为什么不打印？我可以使用其他什么功能？

public class Exercise {

  private static int x = 12;
  private static int y = 28;
  private static double z = 3.3;

  public static void main(String[] args) {
    System.out.println("The answer to(x * y) / 3");
    calculate();
  }

  private static double calculate() {
    double you = (x * y) / z;
    return you;
    System.out.println("you");
  }
}

Answer 1

您正在寻找的更像是：

public class Exercise {

    private static int x = 12;
    private static int y = 28;
    private static double z = 3.3;

    public static void main(String[] args) {
        double result = calculate();
        System.out.println("The answer to (x * y) / z is " + result);
    }

    private static double calculate() {
        double you = (x * y) / z;
        System.out.println("you = " + you);
        return you;
    }
}

正如其他人所说，return必须是该方法的最后一条指令（除非包含在条件中）。您还要小心：打印"you"与打印you变量不同。

Answer 2

在此功能中

private static double calculate() {
    double you = (x * y) / z;
    return you;
    System.out.println("you");
}

System.out.println语句位于return语句之后。这被视为＆＃34;无法到达＆＃34;代码，不会运行。将print语句放在return语句上面。

Answer 3

1.这段代码不会编译。因为，return应该是任何函数中的最后一个语句。返回后的最后一个语句变为不可用的代码，因为在返回之后，编译器停止查找任何语句。

2.在println方法中，“你”已经通过而不是变量你。 println将此“you”作为字符串。正确的代码将是 -

public class Exercise {

private static int x = 12;
private static int y = 28;
private static double z = 3.3;

public static void main(String[] args) {
System.out.println("The answer to(x * y) / 3");
calculate();

}

private static double calculate() {
double you = (x * y) / z;
System.out.println("you" +you);  // pass variable you instead of "you"
return you;


}
}

输出 -

    The answer to(x * y) / 3
    you 101.81818181818183

Answer 4

您在System.out.之前从方法返回。另一种方法可能是：

public class Exercise {

  private static int x = 12;
  private static int y = 28;
  private static double z = 3.3;

  public static void main(String[] args) {
    System.out.println("The answer to(x * y) / 3 = "+ calculate());
  }

  private static double calculate() {
    return (x * y) / z;
  }
}

系统不打印出来吗？

4 个答案: