Question

public static void main(String [] args){
 byte bin[] = new byte[255];
 int a;

 System.out.print("Enter Number: ");
 System.in.read(bin);
 Integer val= Integer.parseInt(new String(bin).trim());

 for(a=1; val >= 0;a++){
   bin[a] = val%2;
   val = val/2;
 }
 System.out.println("Binary: ");
 for(int i = a-1;i >= 0;i--){
   System.out.print(bin[i]);
 }

嗨！这是我的第一个问题。我探讨了一些关于java的问题，我最近对此感兴趣。老实说，我是java的初学者！

使用for，这是我从其他来源获得的解决方案，但这里的问题是错误，我一直在思考高低，我仍然无法删除＆＃34;错误：不兼容的类型：从int到byte的可能有损转换＆＃34;来自第[12]行，包括班级宣言和最终班级＆＃34;}＆＃34;。哦！我正在使用DrJava。

这个程序有问题吗？

Answer 1

您正在尝试bin[a] = val%2; val 整数类型，bin[a] 字节类型。 字节为8位，其中整数为32位。您正尝试在8位内存上输入32位值。这就是它给出不兼容类型错误的原因。

您的代码中存在一些问题。修好它们之后就可以了：

 byte bin[] = new byte[255];
 int a;

 System.out.print("Enter Number: ");
 System.in.read(bin);
 Integer val= Integer.parseInt(new String(bin).trim());

  Integer temp = val; // keep val intact if you want to print it later    

  // Not temp >= 0, it'll run infinite. Also a=0, because later you are printing upto 0
  for (a = 0; temp > 0; a++) { 
      // temp % 2 returns int which doesn't support byte casting
      bin[a] = new Integer(temp % 2).byteValue();
      temp = temp / 2;
  }

  // print binary number
  System.out.print("Binary of " + val + " is = ");
  for (int i = a - 1; i >= 0; i--) {
      System.out.print(bin[i]);
  }

Answer 2

您的代码存在一些问题，但我已对其进行了更正，并添加了注释以获取有关更改的更多信息，此代码也可以使用。试试吧！

import java.util.Scanner;

class Binary
{
    public static void main(String [] args)
    {
        try                                 //Catching the Exception thrown by program is necessary when you use System.in.read(byte[]) so we have used it.
        {
            byte bin[] = new byte[255];
            int a;

            System.out.print("Enter Number: ");
            System.in.read(bin);            //Input will be converted to byte and stored in the byte array 'bin'.
            Integer val= Integer.parseInt(new String(bin).trim());  //Then you're converting it to Integer.
            int Original_val=val;           //Storing the value of 'val' into another variable as it will be changed in the loop so for showing output(if you want to print it) it is required.

            int Bits[]=new int[255];        //Creating integer array where the output(bits 0 or 1 as per calculation) will be stored
            for(a=1; val > 0;a++)           //Here you have written val >=0 which will  make the loop into infinite loop so change it to val > 0.
            {                               
               Bits[a] = val%2;             //Storing the output (Here Answer will be stored from array index '1' as we have started loop from 1.
               val = val/2;
            }

            System.out.println("Binary of "+ Original_val + " is ");        //Here we have used original value because after calculation value of 'val' will be changed.
            for(int i = a-1;i > 0;i--)      //Starting index for storing input is 1 in the loop for the calculation so we will print array till Array index '1'
            {
                System.out.print(Bits[i]);
            }
        }
        catch(Exception e)
        {
            System.out.println("Error:    "+e);
        }
    }
}

一个java控制台程序，它将十进制转换为二进制而不使用预定义的方法（for）

2 个答案: