Converting Between Binary, Octal, Decimal, and Hexadecimal
You want to display an integer as a series of bits, for example when interacting with certain hardware devices. You want to convert a binary number or a hexadecimal value into an integer.
provides the solutions. Use
toBinaryString( ) to convert an integer to binary.
convert a binary string to an
// BinaryDigits.java String bin = "101010"; System.out.println(bin + " as an integer is " + Integer.valueOf(bin, 2)); int i = 42; System.out.println(i + " as binary digits (bits) is " + Integer.toBinaryString(i));
This program prints the binary as an integer, and an integer as binary:
$ java BinaryDigits 101010 as an integer is 42 42 as binary digits (bits) is 101010 $
Integer.valueOf( ) is more general than binary
formatting. It will also convert a string number from any radix to
int, just by changing the second argument.
Octal is base 8,
decimal is 10, hexadecimal 16. Going the other way, the
Integer class includes
toOctalString( ), and
class itself includes a series of
valueOf(double), and so on, that also provide
default formatting. That is, they return the given numeric value
formatted as a string.