Datatype is the declaration of memory location or variable. Data can be of different types and some of the examples of data types in C language are as follows −
Integers, rational numbers, whole numbers, real numbers, complex numbers, vectors, characters etc.
Coming to the machine hardware, the data is everything encoded as a string of binary digits 0 and 1 of finite length. In the machines, the integer data is processed in the arithmetic logic unit (ALU) and fractional data is processed in the floating-point unit (FPU). This gets reflected in the built-in or primitive data types of a high-level language.
Built-in data types
In the C language, there are different built-in data types and some of them are shown below −
Int, float, char, unsigned int, unsigned char, long int, double etc.
Use of data
In the C language the data can be stored in different ways by using different types. Some of the examples are mentioned below −
- char string, grade=’A’;
- int count, index=10;
- float average=6.9;
In the above example chat, int, float are built-in data type, whereas string, grade are variables of type char.
Grade=’A’ initializes the variable grade to character code of ‘A’.
Count and index are variables of type int.
And index=10 initializes the variables to binary representation of 10.
Example
Given below is the C program to find out the size of variable and built-in data type −
#include<stdio.h>
int main(){
int x = 10;
char c;
printf("Size of variable x = %ld bytes\n",sizeof(x));
printf("Size of variable c = %ld byte\n",sizeof(c));
printf("Size of short is %ld bytes\n",sizeof(short));
printf("Size of int is %ld bytes\n",sizeof(int));
printf("Size of long is %ld bytes\n",sizeof(long));
printf("Size of float is %ld bytes\n",sizeof(float));
printf("Size of double is %ld bytes\n",sizeof(double));
printf("Size of long double is %ld bytes\n",sizeof(long double));
printf("Size of char is %ld bytes\n",sizeof(char));
printf("Size of void is %ld bytes\n",sizeof(void));
return 0;
}Output
When the above program is executed, it produces the following result −
Size of variable x = 4 bytes Size of variable c = 1 byte Size of short is 2 bytes Size of int is 4 bytes Size of long is 4 bytes Size of float is 4 bytes Size of double is 8 bytes Size of long double is 16 bytes Size of char is 1 bytes Size of void is 1 bytes