为什么我的二进制到十进制的转换在 java 中不起作用？

Question

I have this method where it converts a binary input from a user to decimal value.

Main Method:

public static void main(String args[])
{
String inputByUserString=""; //number input by the player
int inputByUserInteger;
Scanner sc=new Scanner(System.in);
System.out.println("Enter a number"); //getting the input
inputByUserString=sc.nextLine();
inputByUserInteger=Integer.parseInt(inputByUserString);

and then I create a switch case where there is more options for conversion like Decimal number to Binary number etc...

Then in that switch I call a method:

    int binaryToDecimalNumberVariable=obj1.binaryToDecimalConversion(inputByUserInteger);   
    System.out.println("Binary Number:"+inputByUserInteger);
    System.out.println("Decimal Number:"+binaryToDecimalNumberVariable);

Method for binary to decimal conversion:

public int binaryToDecimalConversion(int inp) //to convert binary number into decimal number
{
int a1;int a2=0;int a3 = 0;
while(inp>0)
{
    a1=inp%10;
    a1=inp/10;
    a3=(int)(a3+(a1*(Math.pow(2,a2)))); //result
    a2++;   
}
return a3;
}

The whole switch case:

  System.out.println("What type of conversion do you want?");
  System.out.println("1)Decimal number to Binary number");
  System.out.println("2)Binary number to Decimal number");
  System.out.println("3)Decimal number to Octal number");
  System.out.println("4)Octal number to Decimal number");
  System.out.println("5)Decimal number to Hexadecimal number");
  System.out.println("6)Hexadecimal number to Decimal number");
  System.out.println("7)Octal number to Hexadecimal number");
  System.out.println("8)Hexadecimal number to Octal number");
  int choice=sc.nextInt();
  switch(choice)
  {
  case 1: //Decimal number to Binary number
  break;
  case 2: //Binary number to Decimal number
    int binaryToDeci=obj1.binaryToDecimalConversion(inputByUserInteger);    
    System.out.println("Binary Number:"+inputByUserInteger);
    System.out.println("Decimal Number:"+binaryToDeci);
break;
case 3: //Decimal number to Octal number
break;
case 4: //Octal number to Decimal number
break;
case 5: //Decimal number to Hexadecimal number
break;
case 6: //Hexadecimal number to Decimal number
break;
case 7: //Octal number to Hexadecimal number
break;
case 8: //Hexadecimal number to Octal number
break;
default:
System.out.println("Invalid Input");
} //switch close

It shows no error while compiling but when I execute it,it just stucks.

Error that is showing when I execute it:

So, help me.

Answer 1

To expand on my comment, the correct way to handle your requirements:

String myBinaryNr = sc.next();
int myNr = Integer.parseInt(myBinaryNr, 2);
String myDecimalNr = Integer.toString(myNr, 10);

The last 10 is optional, since it is the default.

Answer 2

If it's getting stuck, it probably hasn't detected an input and it's awaiting for it. To confirm this, I would add a

System.out.println("Test" + choice);

just under the choice input, so it would be like this:

int choice = sc.nextInt();
System.out.println("Test" + choice);
switch(choice){...}

If it doesn't print correctly, then you have found your issue. It may have something to do with the System.in

Answer 3

Never mind,I just have to do this and it solves the problem.

public int binaryToDecimalConversion(int inp) //to convert binary number into decimal 
{
int a1;int a2=0;int a3 = 0;
while(inp>0)
{
a1=inp%10;
a3=(int)(a3+(a1*(Math.pow(2,a2)))); //result
a2++;   
inp=inp/10;
}
return a3;
}