Variables and constants

The path to learning C is long, and today we begin to learn about variables and constants.

Integer variables are used to store integers, and integer variables can be signed, unsigned, long, and short.

long int amount;//-length integer

Long amount;//length integer type

Signed int total;//signed integral type

Signed total;//signed integral type

unsigned int offset;//unsigned integral type

unsigned offset;//unsigned integral type

short int smallamt;//Quick-integer

Short smallamt;//shorter integer type

Floating-point variable: used to store a real number with a decimal number.

Float amount;//Single Precision type

Double bigamount;//dual Precision Type

Long double reallybigamount;//length dual precision type

Character variable

The characters that are stored are characters in the computer's character set.

Char ch;//declares a character-type variable, and the identifier is ch.

A constant is an immutable quantity and is a constant. Constants are integer constants, floating-point constants, character constants, string constants, escape character constants, and address constants.

Integral type constant

Can be long integer, short integer, signed type, unsigned

Floating-point constants

A floating-point constant consists of an integer and a decimal part:

floatnumber=1.6e10f;//signed floating-point type

All floating-point numbers are defaulted to double.

Character-type constants

The value represented is the value that a character variable can contain, and an ASCII expression can be used to represent a character constant or to denote an escape character with a backslash in single quotation marks.

such as ' A ', ' \x2f ', ' \013 ' \x indicates that the following character is hexadecimal, and that the following character is an octal number.

String constants

A string constant is a string of characters enclosed in double quotation marks.

Escape character

\, single quotation mark

\ \ counter Slash

\ n line break

\ r return character

\ t Horizontal tab

The address constant &counter & is the address character that takes the address of a variable or function.

Variables and constants