Converting 32-bit binary string with Integer.parseInt fails

Question

Why does this part of code fail:

Integer.parseInt(\"11000000000000000000000000000000\",2);

Exception in thread \"main\" java.lang.NumberFormatException: For         


        

Answer 1

Even though your string, "11.....lots of zeros" is a legal binary representation of a negative integer, Integer.parseInt() fails on it. I consider this a bug.

Adding a little levity, since on rereading this post it sounds too pedantic, I understand that Oracle probably doesn't care much whether I think this is a bug or not. :-)

You can try:

   long avoidOverflows = Long.parseLong("11000000000000000000000000000000",2);
   int thisShouldBeANegativeNumber = (int)avoidOverflows);
   System.out.println(avoidOverflows + " -> " + thisShouldBeANegativeNumber);

you should see
3221225472 -> -1073741824

You sometimes have to do this with Colors depending on how they are stored as text.

BTW, exact thing can happen if you are parsing a Hex representation and you are parsing a negative number like "88888888". You need to use Long.parseLong() then convert.