I was seeing how to represent binary numbers in java.
one option is to use as String and use Integer.parseInt() to get the decimal value;
The other option (assignment of 2 to b):
int b = 0b0010; //2
System.out.println(b);
System.out.println(Integer.toBinaryString(-2));
output:
2
11111111111111111111111111111110
using this format, how to represent -2:
int c=??//-b
int values are stored in 32 bits where the most significant bit is the sign.
0b0010; //2
is actually
0b00000000_00000000_00000000_00000010; //2
To convert that to a negative number, you flip the 0s to 1s and the 1s to 0s` and add 1. So
0b00000000_00000000_00000000_00000010; //2
0b11111111_11111111_11111111_11111101
0b11111111_11111111_11111111_11111110; // +1
And so
int b = 0b11111111_11111111_11111111_11111110;
would have the value -2.
0b0010 is sufficient..
-2 in binary, you need to specify all the bits. An alternative way to get -2 is to use the ~ operator as you are suggesting. Another alternative is to just write -2. Another alternative is to write 0 - 2. Ad nauseam.Use the Bitwise NOT operator:
00000000000000000000000000000010 // 2 = 0b0010
00000000000000000000000000000001 // 1 = 0b0010-0b0001
11111111111111111111111111111110 // ~1 = ~(0b0010-0b0001)
11111111111111111111111111111110 // -2 = ~(0b0010-0b0001)
So you just subtract 0b001 and flip all the bits with the ~ Bitwise operator:
int b = ~(0b0010-0b0001); // ~(2-1) = ~1 = -2
System.out.println(b);
System.out.println(Integer.toBinaryString(b));
You are confusing storage with presentation. int b has no base, regardless of whether you assign 2, 0b010 or 0x02 to it. Base 10 is just something println assumes.
You can use Integer.toString(number, radix) to print properly signed binary numbers.
