C Language Data Types

In this tutorial, you will learn the basic data types in C programming, such as int, float, char, etc.

There are the following data types in C language:

In C programming, data type is the declaration of a variable. This determines the type and size of data associated with the variable. For example:

int myVar;

Here, myVar is a variable of int (integer) type. The size of int is4bytes.

Basic type

The following table lists the commonly used basic data types in C language programming.

int (integer)

Integers can have zero, positive, and negative values. For example, 0,-5,10

We can use int to declare an integer variable.

int id;

Here, id is a variable of integer type.

You can declare multiple variables at once in C language programming. For example,

int id, age;

The size of int is usually4bytes (32bits).

float (single precision floating-point number) and double (double precision floating-point number)

float and double are used to store real numbers, that is, numbers with decimal points.

float salary;
double price;

In C language, floating-point numbers can also be expressed in exponential form. For example,

float normalizationFactor =　22.442e2;

What is the difference between float and double?

float (single precision floating-point data type) is4bytes. double (double precision floating-point data type) is8bytes.

char

The keyword char is used to declare a character type variable. For example,

char test = 'h';

The size of a character variable is1bytes.

void

void is an empty type, generally used to indicate the return type of a function, indicating that the function returns nothing.

For example, if a function does not return any content, its return type should be void.

Please note that you cannot create a variable of void type.

The void type specifies no available value. It is usually used in the following three cases:

short and long

If larger numbers are needed, the long type specifier can be used. The method is as follows:

long a;
long long b;
long double c;

Here, variables a and b can store integer values, and c can store floating-point numbers.

is used, then short can be used.32,767, +32,767If the range [−

short d;

You can use the sizeof() operator to check the size of a variable. For example:

#include <stdio.h>　　　　　　
int main() {
　　　　short a;
　　　　long b;
　　　　long long c;
　　　　long double d;
　　　　printf("short byte size = %d bytes\n", sizeof(a));
　　　　printf("long byte size= %d bytes\n", sizeof(b));
　　　　printf("long long byte size= %d bytes\n", sizeof(c));
　　　　printf("long double byte size= %d bytes\n", sizeof(d));
　　　　return 0;
}

Output result:

short byte size=　2　bytes
long byte size=　4　bytes
long long byte size=　8　bytes
long double byte size=　8　bytes

signed and unsigned

In C, signed and unsigned are type modifiers. You can use them to change the data storage of data types. For example,

unsigned int x;
int y;

Here, x, since we use the unsigned modifier, can only store zero and positive values.

Considering the size of int is4bytes, the variable y can store from-2³¹ to 2³¹-1The value, while the variable x can store from⁰ to 2³²-1value.

In C language programming, there are other data types such as:

• Boolean Type

• Enum Types

• Complex Data Types

Derived Data Types

Derived data types are derived from basic data types. For example: arrays, pointers, function types, structures, etc.

We will learn these derived data types in the future tutorials.