Data types are used for declaring different types of variables and functions. This type of variable determines that how much space it taking in storage.
The types in C can be classified as follows −
Types & Description
1.Basic Types: - This is arithmetic type.
It is classified into 2 types –
b.Floating point Types
2.Enumerated types: - This is also arithmetic types and used to define variables that used to assign certain type of discrete integer values.
3.Void type:- This type of data type indicates that there is no value available for return.
4.Derived types :- Derived types list are
(a) Pointer types,
(b) Array types,
(c) Structure types,
(d) Union types and
(e) Function types.
Following Table showing standard integer types and size with their range –
S.no Type Size in bytes Range
1 Char 1 -128 to 127
2 unsigned char 1 0 to 255
3 signed char 1 -128 to 127
4 int 2 -32,768 to 32,767
5 unsigned int 2 0 to 65,535
6 short 2 -32,768 to 32,767
7 unsigned short 2 0 to 65,535
8 long 4 -2,147,483,648 to 2,147,483,647
9 unsigned long 4 0 to 4,294,967,295
Sizeof() operator :
To get the size of a type, sizeof() operator is used.
printf("size for int is : %d ", sizeof(int));
Output : size for int is : 2
Following Table showing standard floating-point types and size with their range –
S. no Type Size in bytes Range Precision
1 float 4 1.2E-38 to 3.4E+38 6
2 double 8 2.3E-308 to 1.7E+308 15
3 long double 10 3.4E-4932 to 1.1E+4932 19
The header file <float.h> is used to allow to use values and other details of binary representation of real numbers in programs.
The following example show that the storage space taken by a float type and its range values −
printf("size for float : %d \n", sizeof(float));
printf("Minimum float positive value: %f\n", min );
printf("Maximum float positive value: %f\n", max );
printf("float place value: %d\n", dig );
The void Type
This void type used to specify that there is no value available to return.
Three kinds of situations of void type –
1.Function returns as void: There are various functions, they don’t return any value or return void. A function has no return value, has the return type as void.
Ex. void exit (int a);
2.Function arguments as void: A function that do not accept any parameter. This function accepts a void.
Ex. int rand(void);
3.Pointers to void: This (pointer of type void *) represents the address of an object, but not its type.
EX. a memory allocation function void *malloc( size_t size );
returns a pointer to void .