Basic data type 1 data type category

Integer: short integer, integer, long integer

Character type: character

Floating-point type: Float and double represent six basic data types in C language.

2. Introduction of various data types

2. 1 integer

Shaping includes short integer, shaping and long integer.

2. 1. 1 short integer

Short a =1;

2. 1.2 integer

Generally, it accounts for 4 bytes (32 bits), with the highest bit representing a symbol, 0 representing a positive number and 1 representing a negative number. The range of values is-2147483648 ~ 2147483647, and the order of storage in memory is first high and then low, for example, 0x 12345678.

Address: 0x0012f780x0012f790x0012ff7a0x0012ff7b.

Data: 78 56 34 12

Definition: use int keyword, for example:

int a = 6；

2. 1.3 long shaping

Length a =10;

2.2 floating-point type

Floating-point type includes single precision type and double precision type.

2.2. 1 single precision type

Floating-point type, also called real type, also called single precision. Usually 4 bytes (32 bits),

Floating a = 4.5

Address: 0x0012f780x0012f790x0012ff7a0x0012ff7b.

Data: 00 00 90 40

Double precision type

Generally 8 bytes (64 bits).

Double? a = 4.5

Address: 0x0012f780x0012f790x0012ff7a0x012ff7b0x012ff7c0x012ff7d0x012ff7e.

Data: 00 00 00 00 00 12 40

2.3 Character types

In various systems, the character type accounts for one byte (8 bits). Defined as follows:

char c = ' a

You can also use ASCII codes corresponding to characters to assign values, as shown below:

char c = 97

Binocular operator of conditional expression b? X:y, calculate condition b first, and then judge. If the value of b is true, calculate the value of x, and the operation result is the value of x; Otherwise, calculate the value of y, and the result is the value of y. Conditional expressions will never evaluate both x and y. Conditional operators are right-associative, that is, they are calculated in groups from right to left. For example, a? B: C? D:e will press a? B: (C? D:e) implementation.