In the C language, the number of bytes for a double, long, unsigned, int, char type data

is related to machine word length and compiler: Therefore, the width of int,long int,short int may vary depending on the compiler. But there are several ironclad principles (Ansi/iso):

1 sizeof (short int) <=sizeof (int)

2 sizeof (int) <=sizeof (long int)

3 short int should be at least 16 bits (2 bytes)

4 a long int should be at least 32 bits.

Unsigned is an unsigned meaning.

For example:

16-bit compilers

Char:1 bytes

char* (i.e. pointer variable): 2 bytes

Short Int:2 bytes

Int:2 bytes

Unsigned int:2 bytes

Float:4 bytes

Double:8 bytes

Long:4 bytes

A long long:8 bytes

Unsigned long:4 bytes

32-bit compilers

Char:1 bytes

char* (i.e. pointer variable): 4 bytes (32-bit addressing space is 2^32, which is 32 bit, or 4 bytes. Similarly 64-bit compilers)

Short Int:2 bytes

Int:4 bytes

Unsigned int:4 bytes

Float:4 bytes

Double:8 bytes

Long:4 bytes

A long long:8 bytes

Unsigned long:4 bytes

64-bit compilers

Char:1 bytes

char* (i.e. pointer variable): 8 bytes

Short Int:2 bytes

Int:4 bytes

Unsigned int:4 bytes

Float:4 bytes

Double:8 bytes

Long:8 bytes

A long long:8 bytes

Unsigned long:8 bytes

In the C language, the number of bytes for a double, long, unsigned, int, char type data