built-in Java classes/methods to convert between binary, decimal, and octal?

Question

hi, i know of several general formulas for converting between binary, decimal, and octal, but i was wondering if java has any built-in methods or classes that convert between the three. for instance, in the Integer class, there are static methods such as toBinaryString, toOctalString, etc which allow for decimal conversion, but i haven't found any to convert the other way. anyone know of anything?

in particular, i am looking for methods to convert from octal and binary to decimal and between octal and binary

thanks! x

Answer 1

How about: parseInt(String s, int radix)

parseInt("-FF", 16) returns -255
parseInt("1100110", 2) returns 102

Answer 2

Integer.parseInt takes an optional second parameter for the base to parse it in. So to get binary,

Integer.parseInt(value, 2);

Octal,

Integer.parseInt(value,8);

Answer 3

You're looking for Integer.parseInt(String s, int radix) and Integer.toBinaryString(int i), Integer.toOctalString(int i) and Integer.toHexString(int i). All of those are static method of the Integer class.

So to turn F hex into 1111 binary:

int fifteen = Integer.parseInt("F", 16);
String fifteenInBinary = Integer.toBinaryString(fifteen);

fifteenInBinary would equal "1111";

Answer 4

i came across that but was under the impression that it was only to decimal. for instance, how would it know that "110101" was binary not decimal? since it could be either technically...maybe i am just over thinking this?

thanks! x