Hexadecimal Addresses in C++

By default, C++ prints addresses in hexadecimal (base 16) to save space. Hexadecimal uses the numeric digits 0 through 9 and the letters 'a' through 'f' to represent the numeric values 10 through 15). Each hex digit is directly equivalent to 4 bits.

Decimal	Hexadecimal	Binary	Decimal	Hexadecimal	Binary
0	0	0000	8	8	1000
1	1	0001	9	9	1001
2	2	0010	10	a	1010
3	3	0011	11	b	1011
4	4	0100	12	c	1100
5	5	0101	13	d	1101
6	6	0110	14	e	1110
7	7	0111	15	f	1111

C++ precedes a hexadecimal value that it prints with the characters "0x" to make it clear that the value is in base 16.

As a C++ programmer, you typically will not need to be able to convert hexadecimal numbers to binary or decimal (or vice versa) or do math in hexadecimal by hand. Both Windows and macOS have calculator apps that can be used to do those things if necessary. What you should be able to do is the following:

Recognize that a value printed by your program or displayed in a debugger is a hexadecimal number and therefore is likely the address of a variable or the value of a pointer variable
Print the address of a variable or the value of a pointer variable in C++ code or in a debugger
Compare two hexadecimal addresses and recognize that they are different (and thus refer to different variables)
Compare two hexadecimal addresses and recognize that they are the same (and thus refer to the same variable)