Question:
How can I get the binary representation of a letter or number?
Forexample, the letter “A” is 100 0001, the letter “B” is 100 0010, etc…
Answer:
You can obtain the individual bits in an integer by anding it witha bitmask that contains a one bit in the position you are fetching andzero bits in all the other positions.
If the result of the and iszero, then that bit is not set, otherwise the bit is set. To printout all of the bits in a number, you can write a loop where you shiftthe bitmask and perform this test for each bit.
In the following codeexample I have written a generalized function that uses this principleto print out a range of bits in an integer.
public class PrintBits { // Doesn't do bounds checking public static void printBits(int number, int begin, int length) { int bitmask; bitmask = 0x80000000 >>> begin; length+=begin; for(int i=begin; i < length; ++i) { if((number & bitmask) == 0) System.out.print('0'); else System.out.print('1'); bitmask >>>= 1; } System.out.println(); } public static void main(String[] args) { for(char ch='A'; ch <= 'Z'; ++ch) // Print the last 8 bits of the character. printBits(ch, 24, 8); }}
