C語言- 指針和結(jié)構(gòu)數(shù)組

在本教程中，我們將學(xué)習(xí)在C編程語言中使用帶有結(jié)構(gòu)體變量數(shù)組的指針。因此，在之前的教程中，我們學(xué)習(xí)了如何為結(jié)構(gòu)體變量創(chuàng)建指針?，F(xiàn)在讓我們繼續(xù)創(chuàng)建一個結(jié)構(gòu)變量數(shù)組并通過指針變量使用它。創(chuàng)建結(jié)構(gòu)體變量數(shù)組在下面的示例中，我們考慮student在上一個教程中創(chuàng)建的結(jié)構(gòu)，并創(chuàng)建一個std大小為3的學(xué)生結(jié)構(gòu)變量數(shù)組來保存三個學(xué)生的詳細(xì)信息。//

student

structurestruct

student

{

char

id[15];

char

firstname[64];

char

lastname[64];

float

points;};//

student

structure

variablestruct

student

std[3];我們可以將std數(shù)組變量表示如下。為結(jié)構(gòu)體創(chuàng)建指針變量現(xiàn)在我們將創(chuàng)建一個指針變量，它將保存學(xué)生結(jié)構(gòu)變量std的起始地址。//

student

structure

pointer

variablestruct

student

*ptr

=

NULL;//

assign

std

to

ptrptr

=

std;筆記！std是一個數(shù)組變量，數(shù)組變量的名稱指向內(nèi)存位置，因此，我們將其分配給結(jié)構(gòu)體指針變量ptr。通過指針訪問結(jié)構(gòu)體數(shù)組變量的每個元素為此，我們首先將指針變量設(shè)置ptr為指向std變量的起始內(nèi)存位置。為此我們寫了ptr=std;.然后，我們可以使用增量運算符來遞增指針變量ptr++，使指針指向結(jié)構(gòu)體數(shù)組變量的下一個元素，即從str[0]到str[1]。因為有三個學(xué)生，所以我們將循環(huán)三遍。因此，我們將指針變量遞增兩次。第一個增量將指針ptr從std[0]移動到std[1]，第二個增量將指針ptr從std[1]移動到std[2]。為了重置指針變量ptr以指向std我們編寫的結(jié)構(gòu)變量的起始內(nèi)存位置ptr=std;。完整代碼#include

<stdio.h>int

main(void)

{

//

student

structure

struct

student

{

char

id[15];

char

firstname[64];

char

lastname[64];

float

points;

};

//

student

structure

variable

struct

student

std[3];

//

student

structure

pointer

variable

struct

student

*ptr

=

NULL;

//

other

variables

int

i;

//

assign

std

to

ptr

ptr

=

std;

//

get

detail

for

user

for

(i

=

0;

i

<

3;

i++)

{

printf("Enter

detail

of

student

#%d

",

(i

+

1));

printf("Enter

ID:

");

scanf("%s",

ptr->id);

printf("Enter

first

name:

");

scanf("%s",

ptr->firstname);

printf("Enter

last

name:

");

scanf("%s",

ptr->lastname);

printf("Enter

Points:

");

scanf("%f",

&ptr->points);

//

update

pointer

to

point

at

next

element

//

of

the

array

std

ptr++;

}

//

reset

pointer

back

to

the

starting

//

address

of

std

array

ptr

=

std;

for

(i

=

0;

i

<

3;

i++)

{

printf("

Detail

of

student

#%d

",

(i

+

1));

//

display

result

via

std

variable

printf("

Result

via

std

");

printf("ID:

%s

",

std[i].id);

printf("First

Name:

%s

",

std[i].firstname);

printf("Last

Name:

%s

",

std[i].lastname);

printf("Points:

%f

",

std[i].points);

//

display

result

via

ptr

variable

printf("

Result

via

ptr

");

printf("ID:

%s

",

ptr->id);

printf("First

Name:

%s

",

ptr->firstname);

printf("Last

Name:

%s

",

ptr->lastname);

printf("Points:

%f

",

ptr->points);

//

update

pointer

to

point

at

next

element

//

of

the

array

std

ptr++;

}

return

0;}輸出：Enter

detail

of

student

#1Enter

ID:

s01Enter

first

name:

YusufEnter

last

name:

ShakeelEnter

Points:

8Enter

detail

of

student

#2Enter

ID:

s02Enter

first

name:

JaneEnter

last

name:

DoeEnter

Points:

9Enter

detail

of

student

#3Enter

ID:

s03Enter

first

name:

JohnEnter

last

name:

DoeEnter

Points:

6Detail

of

student

#1Result

via

stdID:

s01First

Name:

YusufLast

Name:

ShakeelPoints:

8.000000Result

via

ptrID:

s01First

Name:

YusufLast

Name:

ShakeelPoints:

8.000000Detail

of

student

#2Result

via

stdID:

s02First

Name:

JaneLast

Name:

DoePoints:

9.000000Result

via

ptrID:

s02First

Name:

JaneLast

Name:

DoePoints:

9.000000Detail

of

student

#3Result

via

stdID:

s03First

Name:

JohnLast

Name:

DoePoints:

6.000000Result

via

ptrID:

s03First

Name:

JohnLast

Name:

DoePoints:

6.000000我們可以std如下表示內(nèi)存中的數(shù)組變量。注意事項！每個學(xué)生數(shù)據(jù)占用147字節(jié)的內(nèi)存。成員數(shù)據(jù)類型尺寸ID字符15字節(jié)名字符64字節(jié)姓字符64字節(jié)點漂浮4字節(jié)數(shù)組大小為3，總共147x3，即441字節(jié)分配給std數(shù)組變量。第一個元素std[0]獲取從1000到1146的內(nèi)存位置。第二個元素std[1]獲取從1147到1293的內(nèi)存位置。第三個元素std[2]獲取從1294到1440