Forming constant

Decimal integer

Octal integer

Hexadecimal integer

Integer variables include basic integer variables (int), short integers and long integers.

Each kind includes two kinds: signed and unsigned.

Implementation data is also called floating-point variable; Its constant is divided into decimal fraction and exponential form; Variables are divided into single precision double precision and long double precision.

Character data constants include ordinary constants and escape constants in the form of "a" and "a".

Character variables have only one character type.