//Convert Binary Number to Decimal App import java.util.Scanner; public class BinaryToDecimal { public static void main(String[] args) { int r; int s = 0; int p = 1; Scanner in = new Scanner(System.in); System.out.println("Binary to Decimal Convert App"); System.out.println("Enter a Binary Number:");//prompt for binary number to be converted int n= in.nextInt(); { int temp = n; while(n > 0) { r = n % 10; temp = n / 10; if(r!= 0 && r!= 1) { System.out.println("This is not a binary number!"); System.exit(0);//exits if the number is non binary } } System.out.print("Binary="+n); while(n>0) { r=n%10; s=s+(r*p); p=p*2; n=n/10; } System.out.print("Converted to Decimal Number="+s);//generates output } // End Method main }} // End of class

# Binary to Decimal Conversion

Page 1 of 1## 5 Replies - 21895 Views - Last Post: 14 February 2010 - 08:03 PM

### #1 Guest_Theresa Schultz*

# Binary to Decimal Conversion

Posted 14 February 2010 - 02:55 PM

I have an assignment to write a java code to convert a binary number to a decimal number and print it. Here is what I have so far and I am stuck and could realy use some help. Please forgive me because I was really having a hard time wrapping my head around this for some reason. Please give me any help you can; it would be greatly appreciated. The file compiled without errors but it didn't print out anything; it did nothing after I entered the number.

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**Replies To:** Binary to Decimal Conversion

### #2

## Re: Binary to Decimal Conversion

Posted 14 February 2010 - 03:06 PM

So you commented this:

And didn't commented this?

...

System.out.println("Enter a Binary Number:");//prompt for binary number to be converted

And didn't commented this?

int r; int s = 0; int p = 1;

...

### #3 Guest_Theresa Schultz*

## Re: Binary to Decimal Conversion

Posted 14 February 2010 - 03:58 PM

anonymouscodder, on 14 February 2010 - 02:06 PM, said:

So you commented this:

And didn't commented this?

...

System.out.println("Enter a Binary Number:");//prompt for binary number to be converted

And didn't commented this?

int r; int s = 0; int p = 1;

...

I know. I am lost. I tried to get some help from a previous post (http://www.dreamincode.net/forums/index.php?showtopic=153586&st=20) but I think it just confused me more. Maybe I should start over. I have to write a beginner program to convert a binary integer to a decimal integer and they want us to use division and remainder to get there. Can you provide any help? Of course my assignment is due at midnight tonight and I didn't realize I would have so much trouble with this but for some reason I have just hit a brick wall with this and don't know where to start...

### #4

## Re: Binary to Decimal Conversion

Posted 14 February 2010 - 04:14 PM

The reson is that after checking if n is a binary number, the value of n is 0.

then the while loop to convert n to decimal will NEVER execure. because n is never bigger than 0.

you can have two options.

1. you can set a temp variable to hold the value of n, and perform the check on this variable.

2. do both checking and converting in the same loop:

option 2: - converting and checking in the same loop

then the while loop to convert n to decimal will NEVER execure. because n is never bigger than 0.

you can have two options.

1. you can set a temp variable to hold the value of n, and perform the check on this variable.

2. do both checking and converting in the same loop:

option 2: - converting and checking in the same loop

import java.util.Scanner; public class TestClass{ public static void main(String[] args) { //binary value int bin = 0; //decimal value int decimal = 0; //Scanner object Scanner s = new Scanner(System.in); //the pow of 2 int p = 1; //getting binary number System.out.println("Enter Binary Number"); bin = s.nextInt(); //the loop - checking and converting while(bin > 0){ int decimalDig = bin % 10; if(decimalDig != 0 && decimalDig != 1){ System.out.println("Number is not Binary"); System.exit(0); } //converting else { decimal += decimalDig * p; p *= 2; bin /= 10; } } //printing decimal value System.out.println("Decimal Value is: " + decimal); } }

### #5 Guest_Theresa Schultz*

## Re: Binary to Decimal Conversion

Posted 14 February 2010 - 04:33 PM

You are AWESOME! That made SO much more sense to me than what I was trying to do. Thanks SO MUCH!

### #6

## Re: Binary to Decimal Conversion

Posted 14 February 2010 - 08:03 PM

you should really think about naming your variables something more straight forward.

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