Write about Bit Fields in C?
https://www.computersprofessor.com/2016/12/write-about-bit-fields-in-c.html
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The
number of bits required for the structure variable is equal to the sum of the
number of bits required for reach field.
The
structure allows us to specify the numbers of bits of memory to be allocated
for its member fields such fields are called “Bit Fields”.
A
bit field is a set of adjacent bits. Whose size can be from 1 to 16 bits in
length . A word can be divided into a number of bit fields. The name and size
of bits fields are defined using a structure.
The
general form of bit field definition is:
struct tag_name
{
datatype
name1 : bit-length ;
datatype
name2 : bit-length ;
-----------------------------------
-----------------------------------
datatype
namen : bit-length;
}
The
datatype is either int or unsigned int or signed int and the bit –length is
the number of bits used for the specified name.
Note
that the field name is followed by a colon. The bit length is decided by the
range of value to be stored.
Ex:
struct
bit
{
unsigned
int x : 5;
unsigned
int y : 12;
unsigned
int z :10;
}
k;
In
the above example 5 bits are allocated for x, 12 for y and 10 for z. So the
memory required for k is 27 bits. But memory is in the form of bytes. So 4
bytes are allocated for k.
The
bit fields are used to save memory space. We can create effective data structures
Using unions and bit fields.
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