Data Types:
Variables
in a program occupy some space in computer’s memory where some value is stored.
A value to be stored may be an integer, floating point number, a character or a
string etc. But now the question arises that how much memory is allocated to
these values and what is the range of values that can be stored in it as
different types of values don’t occupy some space in memory. So to store these
values, we require different data types depending on the needs of the
application.
C
supports different types of data which may be represented differently within
computer’s memory.
The
data types are divided into three classes:
- Basic or Primary data type
- Derived data type
- User- defined data types
Primary Data Types:
int, char, float and double are basic data types available in
C. They are argumented by using data by using data type qualifiers such as short, long, signed and unsigned. These are used to change the
size or sign of data type.
Integer Type:
Integer type is used to store whole numbers without a
fractional part. In C, the keyword int is used to represent integer quantity.
They generally require 2 bytes of memory
for their storage. This is a signed data type i.e. it can be used to store both
positive as well as negative values.
Range of values that variables of this type can hold lies
between -32768 to 32767.
Declaration of a variable length of int type as follow:
int
length;
Character Type:
The
char type is used to represent individual characters enclosed within single
quotes. Therefore, the char type will generally require 1 byte of memory. Each
char type has an equivalent integer interpretation. The char type data permit
character that has ASCII values extending from -128 to +127. There is also
unsigned char data which permit character that have ASCII values extending from
0 to 255. By default, character data type is treated as unsigned character. The
conversion character used with this data type is %c normally.
Floating Point Types:
The
integer types do not provide the facility to represent decimal numbers so
whenever you represent a number with a decimal such as 3.142 use a floating-
point data type. If you try to use an integer type to type to store a number
with fractional part, the fractional part simply be discarded. C provides two
standard floating- point types: float and double to store numbers with
fractional parts. These give you a choice in the number of digits precision
available to represent your values in the range of values that can be
accommodated.
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