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Printing a Decimal Equivalent of a Binary Number
This problem is from Java How to Program 9e, chapter 4, exercise 31.
It asks me to convert a binary number in to decimal.
How to program this in java? I am not able to find an effective algorithm to convert in to Java.
Help me, please.
Thanks in advance.
Related threads:
Re: Printing a Decimal Equivalent of a Binary Number
Are you talking about Strings that contain numbers as characters?convert a binary number in to decimal.
For example: "0101" and "5"
If not, please explain.
The wrapper classes like Integer and Long have methods for converting a String to a number.
If you don't understand my answer, don't ignore it, ask a question.
Re: Printing a Decimal Equivalent of a Binary Number
That's a problem. If I had to work with strings, I would have done it myself. We have to scan an integer value from CMD using nextInt(). The problem I am facing is that I am not able to find an algorithm to solve the problem.
Re: Printing a Decimal Equivalent of a Binary Number
Well, I think you're going to end up doing it yourself one way or the other, but if you could do it with a String object as an input, I don't see why you can't do it with an int value as an input.If I had to work with strings, I would have done it myself.
Sometimes you have to think up or create an algorithm to solve a problem, and you'll be better for it.
Edit: The book pretty much gives you an algorithm: "[Hint: Use the remainder and division operators to pick off the binary number’s digits one at a time, from right to left. In the decimal number system, the rightmost digit has a positional value of 1 and the next digit to the left a positional value of 10, then 100, then 1000, and so on. The decimal number 234 can be interpreted as 4 * 1 + 3 * 10 + 2 * 100. In the binary number system, the rightmost digit has a positional value of 1, the next digit to the left a positional value of 2, then 4, then 8, and so on. The decimal equivalent of binary 1101 is 1 * 1 + 0 * 2 + 1 * 4 + 1 * 8, or 1 + 0 + 4 + 8 or, 13.]"
Re: Printing a Decimal Equivalent of a Binary Number
First, Scanner has the useRadix(int radix) method. If you used this, the conversion binary-to-decimal would be a "breeze" and I guess this is not the goal of the exercise.Originally Posted by Arslan Ahmad 656
So if you input a number like 10100101 it "seems" a binary number but it really is a decimal number. If you want to think it as a binary .... ok (for the purpose of the exercise). Simply think that each decimal digit is just only 0...1.
As I said in last phrase, you have decimal digits. Use division/modulo operators by 10 to get all decimal digits. A minimal validation is possible, just to check that the value is only 0 or 1. Then you have binary digits 0/1 and you can start multiplying by 2 (or power of 2, depending on the approach) and adding together to obtain the converted decimal value.
Last edited by andbin; February 28th, 2014 at 04:34 PM.
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Re: Printing a Decimal Equivalent of a Binary Number
If the input to the problem is an int value in a variable, what do you want to do with the contents of that variable?integer value from CMD using nextInt()
Given the int value: 123 what do you want to get as output?
If you don't understand my answer, don't ignore it, ask a question.
Re: Printing a Decimal Equivalent of a Binary Number
What would I do if it were a string. I would simply multiply the characters by the increasing powers of two to get the equivalent decimal number.
--- Update ---
No, i am talking about integer input
--- Update ---
Thanks Thanks Thanks!!!! A lot!!
So foolish of mine. I just didn't read the hint; it is really an algorithm in itself. Thanks for reminding me.Solved.
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