课件-第10讲指针

天使与

的化身─指针星期一星期一星期一•可以认为：地址和指针是同义词，变量的指针就是变量的地址星期一211房间100066星期一1000.

.

.

.

.

..

.

.

.

.

.66.

.

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.

.1000星期一数组字符串变量函数常量指针星期一类型*

标识符i

n

t

*

p

i

, *

pc;星期一i

n

t

i

=

0

;i

n

t

*

p

i

= &

i

;char

c =

'

a

'

;char

*pc=

&c;星期一#

include

<stdio.

h>/*

演示指针的定义*/int

main(

){int

i=

0

;char

c=

'a'

;i

n

t

*

p

i

;char

*

pc;pi =

&

i

;pc =

&c;p

r

i

n

t

f

("变量\t

内容\t\t

地址\n");p

r

i

n

t

f

(

"

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

\

n"

);p

r

i

n

t

f

(

"i

\

t

%

d

\

t

\

t

%

p

\

n"

,i,

&

i

)

;p

r

i

n

t

f

(

"c

\

t

%

c

\

t

\

t

%

p

\

n"

,

c

,p

r

i

n

t

f

(

"

p

i

\

t

%

p

\

t

%

p

\

n"

,

p

i

,printf

(

"

pc

\

t%

p

\

t%

p\

n"

,

pc,&

c);&

p

i

)

;&

pc);p

r

i

n

t

f

(

"

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

\

n"

);printf("

pi=%

d\

tpc=%

c\

n",

*

p

i

,

*

pc

)

;r

e

t

u

r

n

0

;}p

o

i

n

t

e

r

1

.

c星期一i

n

t

*p

=

NULL;星期一星期一星期一星期一星期一星期一#

include

<stdio.

h>/*

演示指针的定义*/i

n

t

main(

){i

n

t

*

p

=

NULL;i

n

t

i

=

0

;i

n

ta

[

5

]

=

{

0

,

0

,

0

,

0

,

0

};p

=

&

i

;*p

=

1

;p

r

i

n

t

f

(

"i =

%d\n",

i

);p

=

a

;*p

=

2

;p

r

i

n

t

f

(

"

a

[

0

]=

%d\n",

a

[

0

]);p

=

&

a[

0

];*p

=

3

;p

r

i

n

t

f

(

"

a

[

0

]=

%d\n",

a

[

0

]);p

=

&

a[

4

];*p

=

4

;p

r

i

n

t

f

(

"

a

[

4

]=

%d\n",

a

[

4

]);r

e

t

u

r

n

0

;}p

o

i

n

t

e

r

2

.

c星期一#

include

<stdio.

h>/*

演示指针的赋值*/i

n

t

main(

){i

n

t

a

=

66

;i

n

t

*p=NULL;i

n

t

*q=NULL;p

=

&a;q

=

p

;//

将变量

a

的地址赋给

p//

将

p

的值赋给

qprint

f

("%d

%d

%d\n",

a

, *

p, *

q

);r

e

t

u

r

n

0

;}p

o

i

n

t

e

r

3

.

cp

=

a

;q

=

66

;星期一星期一#

include

<stdio.

h>/*

演示指针加操作*/int

main(

){int

*

p

=

NULL;int

*

q

=

NULL;i++)int

a

[

10

]

;int

i =

0

;for

(i=

0

;

i<

10

;{a

[i] =

i;printf("

a[%

d]

=%

d\

n", i

,

a

[

i

]

)

;}p

r

i

n

t

f

(

"

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

\

n"

);p

=

&

a[

5

];q

=

p+3;p

r

i

n

t

f

(

"

*

p =

%d\t%p\n", *

p

,

p

)

;p

r

i

n

t

f

(

"

*

q =

%d\t%p\n", *

q

,

q

);r

e

t

u

r

n

0

;}add.

c星期一#

include

<stdio.

h>/*

演示指针加减操作*/i

n

t

main(

){a

[

10

]

;i

=

0

;i

n

t

*

p

=

NULL;

i

n

t

*

q

=

NULL;

i

n

ti

n

ti

n

td

i

f

f =

0

;f

o

r

(i=

0

;

i<

10

;

i++){a

[i] =

i;printf("

a[%

d]

=%

d\

n", i

,

a

[

i

]

)

;}p

r

i

n

t

f

(

"

-

--------------

\

n"

);p

=

&

a[

5

];q

=

p

-

3

;d

i

f

f =

p

-

q

;p

r

i

n

t

f

(

"

*

p =

%d\t%p\n",

*

p

,

p

);p

r

i

n

t

f

(

"

*

p =

%d\t%p\n",

*

q

,

q

);p

r

i

n

t

f

(

"

d

i

f

f =

%d\n",

d

i

f

f

)

;r

e

t

u

r

n

0

;}指针的加减运算是以其指向的类型的字长为单位的minus.

c星期一‣pi

==

NULL;

pi

!=

NULL星期一#

include

<stdio.

h>/*

求字符串长度*/i

n

t

main(

){char

s

t

r

[

255

]

;char

*p

=

NULL;s

t

r

)

;i

n

t

l

e

ng

t

h

=

0

;scanf("%

255

s",p

=

s

t

r

;!=

'

\

0'

)w

h

i

l

e

(*p{p++;}l

e

ng

th =

p

- s

t

r

;p

r

i

n

t

f

(

"

L

e

n

g

t

h =

%d", l

e

n

g

t

h

)

;r

e

t

u

r

n

0

;}s

t

r

l

e

n

.

c星期一星期一常量指针星期一#

include

<stdio.

h>/*

演示指针标识数组*/i

n

t

main(

){i

n

t

i=

0

;i

n

t

*p

=

NULL;i

n

t

a

[

5

]

=

{

0

,

1

,

2

,

3

,

4

};p

=

a

;f

o

r

(

i

=

0

;

i<

5

;

i++){p

r

i

n

t

f

(

"

a

[

%

d

]=

%d

%d

%d

%d\n",i,

a

[

i

]

,

p

[

i

]

,

*(

a

+

i

)

,*(

p

+

i

)

)

;}r

e

t

u

r

n

0

;}p

o

i

n

t

e

r

4

.

c星期一i

n

t

*

p;i

n

t

a

[

]

=

{

1

,

2

,

3

}

;p

=

a

;p++;i

n

t

*

p;i

n

t

a

[

]

=

{

1

,

2

,

3

}

;a

=

p

;a++;星期一#

include

<stdio.

h>/*

演示字符指针和字符串*/in

t

main(){charcharchar*sp =

"I

Love C

h

i

n

a

"

;*sv =

NULL;s

t

r

[

] =

"I am

a s

t

u

d

e

n

t

"

;sv =

s

p

;sp =

s

t

r

;s

p

)

;s

v

)

;p

r

i

n

t

f

(

"

%

s

\

n"

,p

r

i

n

t

f

(

"

%

s

\

n"

,r

e

t

u

r

n

0

;}c

h

a

r

_

p

o

i

n

t

e

r

.

c星期一chars

t

r

[

]="

ILoveC

h

i

n

a

"

;char*sp="

ILoveC

h

i

n

a

"

;ILoveChina\

0ILoveChina\

0星期一#

include

<stdio.

h>/*

演示字符指针和字符串*/in

t

main(){charchar*

sp;s

t

r

[

14

];sp

=

"C

Programming";s

t

r

=

"C

Programming";p

r

i

n

t

f

(

"

%

s

\

n"

,p

r

i

n

t

f

(

"

%

s

\

n"

,s

p

)

;s

t

r

)

;r

e

t

u

r

n

0

;}a

r

r

a

y

_

e

r

r

o

r

.

c星期一#

include

<stdio.

h>/*

演示字符指针和字符串*/in

t

main(){charchar*

sp;s

t

r

[

14

];sp

=

"C

Programming";s

t

r

=

"C

Programming";p

r

i

n

t

f

(

"

%

s

\

n"

,p

r

i

n

t

f

(

"

%

s

\

n"

,s

p

)

;s

t

r

)

;r

e

t

u

r

n

0

;}a

r

r

a

y

_

e

r

r

o

r

.

c星期一#

include

<stdio.

h>/*

实现字符串拷贝*/v

o

i

d

s

t

r

_

c

p

y

(

c

h

a

r

*

d

s

t

,

char

*

s

r

c

){!=

'

\

0'

)w

h

i

l

e

(

(*

ds

t

=

*

s

r

c

){dst++;src++;}}int

main(

){charchars

1

[

255

];s2[]="Copya

s

t

r

i

n

g

.

"

;s

t

r

_

c

p

y

(

s

1

,

s

2

)

;p

r

i

n

t

f

(

"

%

s

\

n"

,

s

1

)

;p

r

i

n

t

f

(

"

%

s

\

n"

,

s

2

)

;r

e

t

u

r

n

0

;}s

t

r

c

p

y

.

c星期一char

*

t

)#

include

<stdio.

h>/*

实现字符串比较*/int

str_cmp(

char

*

s

,{f

o

r

(

;

*s

==*t

;

s++,t++){if

(*s ==

'

\

0'

)r

e

t

u

r

n

0

;}r

e

t

u

r

n

*s

-

*

t

;}int

main(

){char

*s1 =

"

ABC";char

*s2 =

"

ABE";int

d

i

f

f=

str_cmp(

s

1

,s

2

)

;p

r

i

n

t

f

(

"

%

d

\

n"

,

d

i

f

f

)

;r

e

t

u

r

n

0

;}strcmp.

c星期一#

include

<stdio.

h>i

n

t

main(){char

s

t

r

1

[

20

]=

"I am

a t

e

a

c

h

e

r

"

;chars

t

r

2s

t

r

2

[

20

]

;=

s

t

r

1

;chars

t

r

3s

t

r

3

[

20

];=

"I am

a t

e

a

c

h

e

r

"

;char

s

t

r

4

[

20

];s

t

r

4

[

]

=

"I am

a t

e

a

c

h

e

r

"

;chars

t

r

5*

s

t

r

5

;=

"I am

a t

e

a

c

h

e

r

"

;char

s

t

r

6

[

20

]

;scanf("%

s", s

t

r

6

)

;char

*

s

t

r

7

;scanf("%

s", s

t

r

7

)

;chars

t

r

8*

s

t

r

8

;=

s

t

r

1

;scanf("%

s",s

t

r

8

)

;r

e

t

u

r

n

0

;}c

h

a

r

_

a

r

r

a

y

_

p

o

i

n

t

e

r

.

c星期一星期一类型

*标识符[

常数表达式]

;i

n

t

*

p

i

[

1

0

]

;.

.

.

.

..

.

.

.

..

.

.

.

..

.

.

.

..

.

.

.

.i

n

t

类型变量i

n

t

类型变量i

n

t

类型变量i

n

t

类型变量星期一char

sname[13][20]={"

"

,

"

J

a

n

u

a

r

y

"

,

"

F

e

b

r

u

a

r

y

"

,

"

March","

A

p

r

i

l

"

,

"

M

a

y

"

,

"

Jun

e"

,

"

J

u

l

y

"

,"

August"

,

"

September","

October"

,

"November",

"December"};char

*pname[13]={"

"

,

"

J

a

n

u

a

r

y

"

,

"

F

e

b

r

u

a

r

y

"

,

"

March","

A

p

r

i

l

"

,

"

M

a

y

"

,

"

Jun

e"

,

"

J

u

l

y

"

,"

August"

,

"

September"

,

"

October"

,

"November",

"December"};sname需要分配13×20=260个char

型内存单元星期一#

include

<stdio.

h>/*

演示字符指针数组*/in

t

main(){char

*name[]={""

,

"

J

a

n

u

a

r

y

"

,

"

F

e

b

r

u

a

r

y

"

,

"

March",

"

A

p

r

i

l

"

,"

May",

"

J

u

n

e

"

,

"

J

u

l

y

"

,

"

August","

September","

O

c

t

o

b

e

r

"

,

"November",

"December"}

;i<

13

;

i++)in

t

i

;f

o

r

(i=

1

;{na

m

e[

i

]

)

;p

r

i

n

t

f

(

"

%

s

\

n"

,}r

e

t

u

r

n

0

;}print_month.

c星期一星期一星期一#

include

<stdio.

h>/*

演示指向指针的指针*/i

n

t

main(){i

n

t

i=

99

;i

n

t

*

p

i =

&i;i

n

t**

ppi =

&

p

i

;p

r

i

n

t

f

(

"

%

p%p%p\

n",&

i

,

pi,p

p

i

)

;p

r

i

n

t

f

(

"

%

d%d%d

\

n",

i

,

*

p

i

,*

*

p

p

i

)

;r

e

t

u

r

n

0

;}p

2

p.

c星期一i

n

t

*

a[

10

];i

n

t

**pa

= &

a[

0

];星期一i

n

t m

a

i

n

(

i

n

ta

r

g

c

,char*

a

r

g

v

[

]

)

;星期一char

*

a

r

g

v

[

]

)#

include

<stdio.

h>/*

打印命令行参数*/i

n

t

m

a

i

n

(

i

n

t

a

r

g

c

,{i

n

t

i

;f

o

r

(i =

0

;

i <

a

r

g

c

;

i++){printf("

argv[%

d]

=%

s\

n",i

, a

r

g

v

[

i

]

)

;}r

e

t

u

r

n

0

;}p

2

p.

c星期一星期一#

include

<stdio.

h>/*

利用指针数组实现命令行参数*/char

*

a

r

g

v

[

]

)int

m

a

i

n

(

int

a

r

g

c

,{int

i;f

o

r

(

i

=

1

;

i<

a

r

g

c

;

i++){argv++;printf("%

s%

s",

*

argv,

(

i

<

a

r

g

c

-

1

)?

"

"

:

""

);}p

r

i

n

t

f

(

"

\

n"

);r

e

t

u

r

n

0

;}echo.

c星期一星期一#

include<stdio.

h>i

n

t

*

py)v

o

i

d

swap(

int

*

px,{i

n

ttemp;temp= *

px;*px =

*

py;*py =

temp;}i

n

t

main(){i

n

t

x=33;i

n

t

y=44;x, y

)

;swap(&x, &

y);printf("

x=%d\ty=%d",r

e

t

u

r

n

0

;}swap.

c星期一星期一i

n

t

*

f

o

o

(

){i

n

t

a

=100;r

e

t

u

r

n

&a;}星期一类型

(*

标识符)

(

参数列表)

;i

n

t

(

*

f

o

o

)

(

i

n

t

x

,

i

n

t

y

)

;星期一#

include

<stdio.

h>/*

演示简单的函数指针*/o

(

c

o

n

s

tchar*

s

t

r

)v

o

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