#72 – Hexadecimal Numbers
August 28, 2010 Leave a comment
In C#, integer literals are normally specified using base-10 notation (e.g. 123), but can also be specified as a base-16 (hexadecimal or hex) number.
Each hex digit represents a 4-bit value and can therefore represent a value in the range [0,15]. Values from 0-9 are represented by their decimal digits. Values from 10-15 are represented by the hex digits A-F.
In C#, hex literals begin with the characters “0x”.
Each hex digit represents a value to be multiplied by a power of 16.
Example: 0x1A2F = (1 x 163) + (10 x 162) + (2 x 161) + (15 x 160) = 4096 + 2560 + 32 + 15 = 6703
You can also think of each hex digit as representing four bits:
0 = 0000
1 = 0001
2 = 0010
…
E = 1110
F = 1111
So 0x1A2F would be: 0001 1010 0010 1111
In C#, you can use hex numbers for integer literals.
int n = 0x1A2F; ushort u1 = 0xFFFF; // 16 bits uint u2 = 0x12341234; // 32 bits
Hex numbers are a convenient way of expressing integral values, denoting exactly the bits stored in memory for that integer.
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