How to convert Hex String to binary string with leading zeros?

Question

Suppose I have a hex String as 0F0A. I need the output as 0000111100001010. I tried the following method but this returns 111100001010 - I need the leading 0000 as well.

public static String hexToBinary(String hex) {
    return new BigInteger(hex, 16).toString(2);
}

You must refer this question, I hope this will definately help http://stackoverflow.com/questions/9246326/convert-hexadecimal-string-hex-to-a-binary-string This might help. — Ajit Hogade
– Ajit Hogade, Commented Nov 17, 2015 at 7:50

ΦXocę 웃 Пepeúpa ツ · Accepted Answer · 2015-11-17 07:12:13Z

3

you are almost there... just need to format it:

   String string = "0f0a";
   String value = new BigInteger(string, 16).toString(2);
   String formatPad = "%" + (string.length() * 4) + "s";
   System.out.println(String.format(formatPad, value).replace(" ", "0"));

the formatPad is the padder (4 bit for each hex symbol)... in your case 16

edited Nov 17, 2015 at 7:12

answered Nov 17, 2015 at 6:57

ΦXocę 웃 Пepeúpa ツ

48.4k17 gold badges77 silver badges102 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

ajb Over a year ago

And what if he doesn't know beforehand how long his input string is?

ajb Over a year ago

OK, thanks for demonstrating it. I don't think beginners always realize they can compute a format string. I strongly suggest you put string.length() * 4 in parentheses. Since the + is string concatenation and * is arithmetic multiplication, you really shouldn't combine the two types in the same expression without parentheses; I've seen things like String1 + number + 1 or String1 + number - 1 too often, which doesn't work. Yours will work due to operator precedence, but it's a bit confusing without the parens.

Tsung-Ting Kuo · Accepted Answer · 2015-11-17 07:01:06Z

-1

Try this code:

String hexToBinary(String hexString) {
    int i = Integer.parseInt(hexString, 16);
    String binaryString = Integer.toBinaryString(i);
    String padded = String.format("%8s", Integer.toBinaryString(i)).replace(' ', '0') 
    return padded;
}

edited Nov 17, 2015 at 7:01

Tsung-Ting Kuo

1,1706 gold badges17 silver badges23 bronze badges

answered Nov 17, 2015 at 6:58

Anukul Mittal

295 bronze badges

1 Comment

ajb Over a year ago

And if his input is too large to fit in an Integer? The OP didn't say anything about how long his input string could be. And your code will not give him the output he wants on the input he specified--did you try it?

Collectives™ on Stack Overflow

How to convert Hex String to binary string with leading zeros?

2 Answers 2

2 Comments

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related