C Language Blog (5) How does the programming base understand octal and hexadecimal?

In the C language learning programming process, in addition to the binary, programming also often use octal and hexadecimal. These are also the basic programming of teaching, to become the C-language of the great God, it must be understood clearly.

Octal has 0~7 a total of 8 numbers, the base is 8, every eight into one, borrow one when eight; hexadecimal, with a to indicate that the 12,d means that 13,e represents 14,f 15, so there are 0~f a total of 16 numbers, the base is 16, every 16 into 1, borrow 1 when 16. For example:

• Octal 3072 = 3x83 + 0x82 + 7x81 + 2x80 = 1536 + 0 + 56 + 2 = 1594
• Hex e3f9 = 14x163 + 3x162 + 15x161 + 9x160 = 57344 + 768 + 240 + 9 = 58361

Binary Binary

Binary , octal, decimal, hexadecimal correspondence

decimal		octal	hexadecimal	decimal		octal	hexadecimal
0	0	0	0	10	1010	12	A
1	1	1	1	11	1011	13	B
2	10	2	2	12	1100	14	C
3	11	3	3	13	1101	15	D
4	100	4	4	14	1110	16	E
5	101	5	5	15	1111	17	F
6	110	6	6	16	10000	20	10
7	111	7	7	17	10001	21st	11
8	1000	10	8	18	10010	22	12
9	1001	11	9	19	10011	23	13

In C, octal usually begins with "0" (note that it is the number 0, not the letter O), such as 0307, and hexadecimal usually begins with "0x" or "0X" (case insensitive), such as 0xe27 or 0x89f.

Let's look at two examples of octal and hexadecimal addition operations.

1) octal addition: 0107 + 0274 = 0403

Figure 1: octal addition operation

2) Hex addition: 0xa2b + 0x276 = 0XCA1

Figure 2: Hexadecimal addition operation This is the basic teaching of programming for the general population, I will be in this C-language blog every time to update some of the basic programming needs of beginners next we want to introduce the conversion between the problem, please look forward to!

C Language Blog (5) How does the programming base understand octal and hexadecimal?