Abl-electronic PIC Microcontrollers PIC16 Manuel d'utilisateur télécharger pdf (Page 120)

Sizeof Operator

Prefix unary operator sizeof returns an integer constant that gives the size in

bytes of how much memory space is used by its operand (determined by its type,

with some exceptions).

Operator

sizeof can take either a type identifier or an unary expression as an

operand. You cannot use

sizeof with expressions of function type, incomplete

types, parenthesized names of such types, or with an lvalue that designates a bit

field object.

Sizeof Applied to Expression

If applied to expression, size of the operand is determined without evaluating the

expression (and therefore without side effects). Result of the operation will be the

size of the type of the expression’s result.

Sizeof Applied to Type

If applied to a type identifier,

sizeof returns the size of the specified type. Unit

for type size is the sizeof(char) which is equivalent to one byte. Operation

sizeof(char) gives the result 1, whether the char is signed or unsigned.

sizeof(char)

/* returns 1 */

sizeof(int)

/* returns 2 */

sizeof(unsigned long)

/* returns 4 */

When the operand is a non-parameter of array type, the result is the total number

of bytes in the array (in other words, an array name is not converted to a pointer

type):

int i, j, a[10];

//...

j = sizeof(a[1]);

/* j = sizeof(int) = 2 */

i = sizeof(a);

/* i = 10*sizeof(int) = 20 */

If the operand is a parameter declared as array type or function type, sizeof

gives the size of the pointer. When applied to structures and unions, sizeof gives

the total number of bytes, including any padding. Operator

sizeof cannot be

applied to a function.

mikroC

- C Compiler for Microchip PIC microcontrollers

mikroC

making it simple...

112

MikroElektronika:

Development

tools

Books

Compilers

page

1 2 ... 115 116 117 118 119 120 121 122 123 124 125 ... 311 312

Commentaires sur ces manuels

Pas de commentaire

Abl-electronic PIC Microcontrollers PIC16 Manuel d'utilisateur Page 120

Commentaires sur ces manuels