Dear Iftikhar,
System.out.println(Integer.toBinaryString(4));
API:
public static
String toBinaryString(int i)
Creates a string representation of the integer argument as an unsigned integer in base 2.
The unsigned integer value is the argument plus 232if the argument is negative; otherwise it is
equal to the argument. This value is converted to a string of ASCII digits in binary (base 2)
with no extra leading 0s. If the unsigned magnitude is zero, it is represented by a single zero
character '0' ('\u0030'); otherwise, the first character of the representation of the
unsigned magnitude will not be the zero character. The characters '0' ('\u0030') and '1'
('\u0031') are used as binary digits.
Parameters:
i - an integer.
Returns:
the string representation of the unsigned integer value represented by the argument in
binary (base 2).