Data Types in C

Data Types in C

To decide how much memory is allocate for that particular variable and which operation should be performed is depend on a Data Types.

Classification Of Data Types:-

1. Basic/ Primitive/ Predefined data types

2.Derived data types

3. User defined data types

I. Basic/ Primitive/ Predefined Data Types:-

• Data types which are already declared or defined by a language designer is known as Basic/ Primitive/ Predefined data types.
• Following are the basic data types:

1. integer(int)
2. character(char)
3. single point precision(float)
4. double point precision(double)
5. No value available(void)

II. Derived Data Types:-

• Derived data types do not create or declare a new data type.
• They add some functionality to the basic data types.
• Following are the derived data types.

1. Array:-    e.g.: char [ ], int [ ], etc.
2. Pointer:-    e.g.: char*, int*, etc.
3. Function:-    e.g.: int(int, int), float(int) etc.

III.User Defined data Types:-

• Data types which are defined or declared by a user itself is known as user defined data types.
• Following are the user defined data types:

1. Structure(struct)
2. Union(union)
3. Enumeration(enum)

So these are various data types. Further we are going to learn more about particular data types.

Data Type Qualifier :-

• They are used to indicate the special properties of data within an object.
• There are two types:-

1.  const qualifier:- Declaring an object or variable const indicates that its value will not be changed throughout the program.
2. volatile qualifier:- Declaring an object or variable volatile indicates that the value of the variable may change at any time throughout the program.

Data Type Modifier:-

• The type modifier modifies or change the range and the arithmetic properties of basic data type.
• There are four Data Type Modifiers:-

1. signed int:- It is used to store magnitude of a variable. In case of signed integer, out of 32 bits, we can use 31 bits.
2. unsigned int:- In case of unsigned modifier, user can use all 32 bits.By default, unsigned modifier is assigned by the compiler.
3. short int:-short modifier modifies the size of a variable.
4. long int:-long modifier modifies the size of a variable.By default, long modifier is assigned by a compiler.

example:-

signed int i;        //last bit is used to store magnitude

unsigned int i;   //all 32 bits we can use

short int i;        //size will be modified. size of (i)=2 bytes.

long int i;        //size of (i)=4 bytes

Data types and its memory storage and ranges in C

• Each data type has different memory requirement and perform specific operations accordingly.
• The memory of Data types may vary(i.e. change) from compiler to compiler.
• Also the Ranges of data types may also vary from compiler to compiler.
• Ranges defines that upto which number the data types can stored values.

So here we have listed the Data types and their memory requirement and their ranges in C language. They are as follows:-   

Sr. No	Data Types	Turbo C		MS Visual Studio
		Memory	Ranges	Memory	Ranges
1	Char	1 Byte	-128 to 127	1 Byte	-128 to 127
2	int	2 Bytes	-32768 to 32767	4 Bytes	-2147783648 to 2147483647
3	float	4 Bytes	3.4* 10-38 to 3.4*1038	4 Bytes	3.4* 10-38 to 3.4*1038
4	double	8 Bytes	1.7*10-308 to 1.7*10308	8 Bytes	1.7*10-308 to 1.7*10308
5	Signed char	2 Bytes	-128 to 127	1 Byte	-128 to 127
6	Signed int	1 Byte	-32768 to 32767	4 Bytes	-2147483648 to 2147483647
7	Unsigned char	1 Byte	0 to 255	1 Byte	0 to 255
8	Unsigned int	2 Byte	0 to 65535	4 Bytes	4294967295
9	Short int	2 Bytes	-32768 to 32767	2 Bytes	-32768 to 32767
10	Long int	4 Bytes	-	4 Bytes	-
11	Long float	8 Bytes	-	8 Bytes	-
12	Long double	10 Bytes	3.4*10-4932 to 1.1*104932	8 Bytes	1.7*10-308 to 1.7*10308
13	void	Object of void type cannot be created

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Let us see an example for a size of an integer and its range.

#include <stdio.h>int main()
{    
     int a = 1;
   printf("value is %d and size is %lu bytes \n", a,sizeof(int)); //%d indicates an integer and                                                                                                                  //%lu indicates unsigned int
     return 0;
}

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To check the size (i.e. memory requirement) of variable of any of the data types, "sizeof( data_type)" is used.