Data Types Of C

C Data Types – Complete Guide

1. What is a Data Type?

A data type in C defines:

• The type of data a variable can store.
• The size (in bytes) of that data.
• The range of values it can hold.
• The format specifier to use when printing or reading it.

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2. Basic Data Types Table

Data Type	Size*	Description
int	4 bytes	Whole numbers (integers)
float	4 bytes	Decimal numbers (single precision)
double	8 bytes	Decimal numbers (double precision)
char	1 byte	Single character
void	0 bytes	Represents “no type” (used in functions)

*Sizes may vary depending on the compiler and system.

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3. Extended Data Types and Ranges

Data Type	Size*	Range	Format Specifier
bool (from <stdbool.h>)	1 byte	true / false	%d
char	1 byte	-128 to 127	%c / %d
unsigned char	1 byte	0 to 255	%c / %d
short	2 bytes	-32,768 to 32,767	%d
unsigned short	2 bytes	0 to 65,535	%d
int	4 bytes	-2,147,483,648 to 2,147,483,647	%d
unsigned int	4 bytes	0 to 4,294,967,295	%u
long long int	8 bytes	-9 quintillion to +9 quintillion	%lld
unsigned long long int	8 bytes	0 to 18 quintillion	%llu
float	4 bytes	~6–7 decimal digits precision	%f
double	8 bytes	~15–16 decimal digits precision	%lf

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4. Example Usage

#include <stdio.h>
#include <stdbool.h> // for bool

int main() {
    char a = 'C';                   // single character
    char b[] = "Bro";               // string (array of chars)

    float c = 3.141592;              // single precision
    double d = 3.141592653589793;    // double precision

    bool e = true;                   // boolean

    char f = 120;                    // char as number
    unsigned char g = 255;           // unsigned char

    short h = 32767;                 // short integer
    unsigned short i = 65535;        // unsigned short

    int j = 2147483647;              // int
    unsigned int k = 4294967295;     // unsigned int

    long long int l = 9223372036854775807LL; // long long
    unsigned long long int m = 18446744073709551615ULL; // unsigned long long

    printf("%c\n", a);    // char
    printf("%s\n", b);    // string
    printf("%f\n", c);    // float
    printf("%lf\n", d);   // double
    printf("%d\n", e);    // bool
    printf("%d\n", f);    // char as number
    printf("%d\n", g);    // unsigned char as number
    printf("%d\n", h);    // short
    printf("%d\n", i);    // unsigned short
    printf("%d\n", j);    // int
    printf("%u\n", k);    // unsigned int
    printf("%lld\n", l);  // long long int
    printf("%llu\n", m);  // unsigned long long int

    return 0;
}