Explain the various data types used in C with suitable examples.
C language has a rich set of data
types. Storage representations and machine instruction to handle constants
differ from machine to machine. The variety of data types available allow the
programmer to select the type appropriate to the needs of the application as
well as the machine.
C supports three classes of data
types:
1.
Primary or Fundamental data types: This includes char, int, float, and
void data types.
2.
Derived data types: This includes pointer and array.
3.
User-defined data types: This includes structure and unions.
Ø
Integer Types:
Integers are whole numbers with a range
of values supported by a particular machine. Integers occupy one word of
storage, and since the word size of machines vary (16 or 32 bit) the size of
the integer that can be stored depends on the computer. If we use a 16 bit word
length, the size of the integer value is limited to the range -32768 to +32767
(that is -215 to +215
-1). A signed integer uses one bit for sign and 15 bits for the magnitude of
the number. Similarly, a 32 word length can store an integer ranging from
-2,147,438,648 to +2,147,483,647.
C has three classes of integer
storage. Namely short int, int and long int. in both signed and unsigned forms.
Ø
Character Types:
A single character can be defined as
character (char) type data. Characters are usually stored in 8 bits (one byte) of
internal storage. The qualifier signed or unsigned may be explicitly applied to
char. While unsigned chars have values between 0 and 255, signed char have
values from -128 to +127.
Ø
Floating Point Types:
Floating point or real number are
stored in 32 bits (on all 16 bit and 32 bit machines), with 6 digits of
precision. Floating point numbers are defined in C by the keyword float. When
the accuracy provided by a float number is not sufficient, the type double cab
be use to define the number. A double data type number uses 64 bits giving a
precision of 14 digits. These are known as double precision numbers.
Ø
Void Types:
The void types has no values. This is
usually used to specify the type of functions. The type of a function is said
to be void when it does not return any value to the calling function. It also
play the role of a generic type, meaning that it can any of the other standard
type.
Following tables shows the Size
and Range of Data Types on a 16-bit Machine:
 |
Type Size (bits/bytes) Range
char
or signed char 8 / 1 -128
to 127
unsigned
char 8 / 1 0 to
255
int
or signed int 16 / 2 -32,768
to +32,767
unsigned
int 16 / 2 0 to
65,535
short
int or
unsigned
short int 8 / 1 -128
to 127
signed
short int 8 / 1 0 to
255
long
int or -2,147,483,648
to
signed
long int 32 / 4 +2,147,483,647
unsigned
long int 32 / 4 0 to
4,294,967,295
float 64 / 8 3.4E -
38 to 3.4E + 38
double
64 / 8 1.7E-308
to 1.7E+308
long
double 80 / 10 3.4E-4932
to 1.1E-4932
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