Datatypes

Data types

Integer

Allowed types are char and int;

signed char

8 bit, from -128 to 127.

unsigned char

8 bit, from 0 to 255.

char

8 bit, used to store ASCII, ex; 'h', '\n', etc...

short int

16 bit, from -32,768 to 32,767.

unsigned short int

16 bit, from 0 to 65,535.

int

32 bit, from -2,147,483,648 to 2,147,483,647.

unsigned int

32 bit, from 0 to 4,294,967,295.

long int

32 bit, from -2,147,483,648 to 2,147,483,647.

unsigned long int

32 bit, from 0 to 4,294,967,295.

long long int

64 bit, from 9,223,372,036,854,775,808 to 9,223,372,036,854,775,807.

unsigned long long int

64 bit, from 0 to 18,446,744,073,709,551,615.

Real number

Real numbers are fractional numbers, all floating points are signed. Check float.h.

float

From 1e-37 to 1e37

double

Largest of floating point.

long double

The long double data maybe larger than double

Complex number

Complex Number Types

Enumeration

        enum colors {black, orange, blue} color;
        enum colors color;
        

Unions

        union accounts {
            int id;
            float value;
        } first_account, second_account;
        

Structures

        struct point {
            int x, y;
        } first_point;
        struct point second_point;
        

Arrays

        int account_array[9];
        int account_array[] = {0, 1, 2, 3};
        int account_array[] = {0, 1, 2, [9] = 9};
        

        int account_array[2][9] { {1,2,3},{9,8,7} }
        

Initializing string with individual characters the null character must be defined;

        char black[] = {'b', 'l', 'a', 'c', 'k', '\0'}
        

        char black[] = "black";
        

        union accounts {
            int id;
            float value;
        };
        union accounts accounts_array[9];
        accounts_array[0].id = 8;
        

        struct point {
            int x, y;
        };
        struct point point_array[9];
        point_array[0].x=2;
        point_array[0].y=3;
        

Pointers

Incomplete types

Type qualifiers

Storage class

This is part of the c9-doc Manual. Copyright (C) 2018 c9 team. See the file Gnu Free Documentation License for copying conditions.