C language 1.15

Hex (HW) By now, you've noticed that pointers (which we've claimed are numbers) have letters in them, as in: address 0x7fff5eb8859c Let's now explain the hexadecimal notation: Recall: a decimal number uses ten digit symbols 0,1,2..,9. A binary number uses two symbols: O and 1 A hexadecimal number uses 16 symbols. The first ten of these are the same ten used for decimal: O through 9. What symbols could we use for the remaining six? In an ideal world, one would invent new characters. But our keyboard is limited. So, the convention is to use the letters a,b,c,d,e,f. (Either lowercase or uppercase). How do we understand the value of a hexadecimal number? Recall the meaning of the placement of digits in our own decimal system: 4 2x100 4x10 3x1 The first digit (going right to left), 3, is the number of units or 3x10 The second digit, 4, is the number of tens or 4x10 The third digit, 2, is the number of hundreds or 2x102