How to store a binary value into a byte array

Question

i have used the following statement byte[3]=(byte)0x80 0x80 is an hex value of 128 and i have also tried this statement byte[3]=(byte) 128

in the first case, while printing i am getting the output as -128 in the second case, output is -1

Now how can i solve this. Is there any other way to store 10000000 into a byte array

Peter Lawrey · Accepted Answer · 2011-06-20 08:42:31Z

3

The problem is not how you put the value in, its how you get it out.

byte[] bytes = new byte[4];
bytes[3] = (byte) 128;
int num = bytes[3] & 0xFF; 
System.out.println(num);

prints

answered Jun 20, 2011 at 8:42

Peter Lawrey

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Comments

Connman · Accepted Answer · 2011-06-20 08:44:11Z

1

The computer stores the value in binary anyway, seems like your problem is outputting it in binary form.

Integer.toBinaryString(byte[3]);

should do the trick.

Edit: misread your question, but as others have said you will need to make sure the variable is unsigned to store a positive value over 127.

answered Jun 20, 2011 at 8:44

Connman

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Andy · Accepted Answer · 2011-06-20 09:11:08Z

0

A[0]=      x  & 255
A[1]= (x>> 8) & 255
A[2]= (x>>16) & 255
A[3]= (x>>24) & 255
...

answered Jun 20, 2011 at 9:11

Andy

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