C Data Types
A data type is a set of values and is determined to work on those values.
Data types are used for declaring variables or functions of different types in C.
The type of variables determines how much space occupied by variables in memory.
Data types are classified as follows:
- Primary data type
-Character (char)
-Integer (int)
-Float
-Double
-Void
- Secondary data type
-Array
-Pointer
-Structure
-Union
-Enum and etc.
Integer Types
| Type | Storage size | Value range |
|---|
| char |
1 byte |
-128 to 127 or 0 to 255 |
| unsigned char |
1 byte |
0 to 255 |
| signed char |
1 byte |
-128 to 127 |
| int |
2 or 4 bytes |
-32,768 to 32,767 or -2,147,483,648 to 2,147,483,647 |
| unsigned int |
2 or 4 bytes |
0 to 65,535 or 0 to 4,294,967,295 |
| short |
2 bytes |
-32,768 to 32,767 |
| unsigned short |
2 bytes |
0 to 65,535 |
| long |
4 bytes |
-2,147,483,648 to 2,147,483,647 |
| unsigned long |
4 bytes |
0 to 4,294,967,295 |
Floating Types
| Type | Storage size | Value range | Precision |
|---|
| float |
4 byte |
1.2E-38 to 3.4E+38 |
6 decimal places |
| double |
8 byte |
2.3E-308 to 1.7E+308 |
15 decimal places |
| long double |
10 byte |
3.4E-4932 to 1.1E+4932 |
19 decimal places |
sizeof operator
We can use sizeof operator for determining the size of variables on a particular system.
Example:
#include <stdio.h>
#include <limits.h>
void main() {
printf("Storage size for int : %d \n", sizeof(int));
}
Output:
Storage size for int : 4 (on LINUX operating system)
Another classification of data types as follows:
- Fundamental data types
- void (denote the type with no values)
- int (denote an integer type)
- char (denote a character type)
- float,double (denote a floating point type)
- int*,float*,char* (denote a pointer type)
- Derived data types
- array (collection of same data types)
- string (collection of character variables)
- structure (collection of same and/or different data types)
