Question

我正在尝试使用此公式查找区域，但是，变量a，b和c未初始化。如何初始化它们并让它们与扫描仪一起使用？

import java.text.DecimalFormat;
import java.util.Scanner;
public class PA2 
{   
   public static void main(String[] args)
   {
       Scanner scan = new Scanner(System.in);
       DecimalFormat fmt = new DecimalFormat ("0.##");

       float a, b, c;
       float s = (a + b + c);
       float pt1, pt2, pt3, pt4, pt5, pt6;
       double Area;

       pt1 = (s - a);
       pt2 = (s - b);
       pt3 = (s - c);
       pt4 = (s * pt1);
       pt5 = (pt4 * pt2);
       pt6 = (pt5 * pt3);
       Area = Math.sqrt(pt6);

       System.out.println("Enter first side: ");
       a = scan.nextFloat();
       System.out.println("Enter second side: ");
       b = scan.nextFloat();
       System.out.println("Enter third side: ");
       c = scan.nextFloat();
       System.out.println("Your area is: " + fmt.format(Area));

   }
}

Answer 1

在开始编写代码之前，在文章中定义顺序和算法是一个好习惯......

你的方法并不是那么糟糕，只需在代码中订购序列：

Scanner scan = new Scanner(System.in);
DecimalFormat fmt = new DecimalFormat ("0.##");

//1. delcare the variables and initialize it...
float a = 0f;
float b = 0f;
float c = 0f;

//2. get the input 
System.out.println("Enter first side: ");
a = scan.nextFloat();
System.out.println("Enter second side: ");
b = scan.nextFloat();
System.out.println("Enter third side: ");
c = scan.nextFloat();

//3. Do the Math behind the scenes

float s = (a + b + c);
float pt1, pt2, pt3, pt4, pt5, pt6;
double Area;
pt1 = (s - a);
pt2 = (s - b);
pt3 = (s - c);
pt4 = (s * pt1);
pt5 = (pt4 * pt2);
pt6 = (pt5 * pt3);
Area = Math.sqrt(pt6);

//4. Print the results....
System.out.println("Your area is: " + fmt.format(Area));

Answer 2

只需这样做，而不仅仅是

float a, b, c;

它的：

float a=0;
float b=0;
float c=0;

初始化变量。我和另一个程序有同样的问题。希望这会有所帮助。

如何初始化变量并让它们与扫描仪一起使用？

2 个答案: