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第八章指针C程序设计中使用指针可以:使程序简洁、紧凑、高效有效地表示复杂的数据结构动态分配内存得到多于一个的函数返回值Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfi
le5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.§8
.1指针的概念变量与地址程序中:inti;floatk;内存中每个字节有一个编号-----地址…...…...2000200120022005内存02003ik编译或函数调用时为其分配内存单元变量是对程序中数据
存储空间的抽象Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedw
ithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.…...…...2000200420062005整型变量i10
变量i_pointer200120022003指针与指针变量指针:一个变量的地址指针变量:专门存放变量地址的变量叫~2000指针指针变量变量的内容变量的地址指针变量变量变量地址(指针)变量值指向地址存入指针变量Evaluationonly.eatedwithAs
pose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NE
T3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.&与*运算符含义含义:取变量的地址单目运算符优先级:2结合性:自右向左含义:取指针所指向变量的内容单目运算符优先级:2结合性:自右向左两者关系:互为逆运算
理解…...…...2000200420062005整型变量i10变量i_pointer2001200220032000指针变量i_pointer-----指针变量,它的内容是地址量*i_pointer----指针的目标变量,它的内容是数据&i_pointer---
指针变量占用内存的地址200010i_pointer*i_pointer&i_pointerii_pointer&i&(*i_pointer)i*i_pointer*(&i)i_pointer=&i=&(*i_pointer)i=*
i_pointer=*(&i)Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationo
nly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.直接访问与间接访问直接访问:按变量地址存取变量值间接访问:通过存放
变量地址的变量去访问变量例i=3;-----直接访问指针变量…...…...2000200420062005整型变量i10变量i_pointer20012002200320003例*i_pointer=20;-----间接访问20Evaluationonly.eatedwithAspos
e.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-201
1AsposePtyLtd.指针变量…...…...2000200420062005整型变量i10变量i_pointer2001200220032000整型变量k例k=i;--直接访问k=*i_pointer
;--间接访问10例k=i;k=*i_pointer;Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluati
ononly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.§8.2指针变量指针变量与其所指向的变量之间的关系指针变量的定义一般形式:[存
储类型]数据类型*指针名;3变量i2000i_pointer*i_pointeri*i_pointer&ii_pointeri=3;*i_pointer=33变量i2000i_pointer*i_pointeri*i_pointer&ii_pointeri=3;*i_pointer=3合法标识符指
针变量本身的存储类型指针的目标变量的数据类型表示定义指针变量不是‘*’运算符例int*p1,*p2;float*q;staticchar*name;注意:1、int*p1,*p2;与int*p1,p2;2、指针变量名是p1,p2,不是*p1,*p23、指针变量只能指向定
义时所规定类型的变量4、指针变量定义后,变量值不确定,应用前必须先赋值Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-20
11AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.指针变量的初始化一般形式:[存储类型]数据
类型*指针名=初始地址值;赋给指针变量,不是赋给目标变量例inti;int*p=&i;变量必须已说明过类型应一致例int*p=&i;inti;例inti;int*p=&i;int*q=p;用已初始化指针变量作初值例main(){int
i;staticint*p=&i;..............}()不能用auto变量的地址去初始化static型指针Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Cop
yright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2
011AsposePtyLtd.例main(){inti=10;int*p;*p=i;printf(“%d”,*p);}危险!例main(){inti=10,k;int*p;p=&k;*p=i;printf(“%d”,*p);}指针变量必须先赋值,再使用…...…...200020
0420062005整型变量i10指针变量p200120022003随机Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.ea
tedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.零指针与空类型指针零指针:(空指针)定义:指针变量值为零表示:int
*p=0;p指向地址为0的单元,系统保证该单元不作它用表示指针变量值没有意义#defineNULL0int*p=NULL:p=NULL与未对p赋值不同用途:避免指针变量的非法引用在程序中常作为状态比较例int*p;......while(p!=NULL){...…}void*类型指针
表示:void*p;使用时要进行强制类型转换例char*p1;void*p2;p1=(char*)p2;p2=(void*)p1;表示不指定p是指向哪一种类型数据的指针变量Evaluationonly.eatedwithAspose.Slidesfor.N
ET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2
011AsposePtyLtd.例指针的概念main(){inta;int*pa=&a;a=10;printf("a:%d\n",a);printf("*pa:%d\n",*pa);printf("&a:%x(hex)\n",&a);printf("pa:%x(hex)\n"
,pa);printf("&pa:%x(hex)\n",&pa);}运行结果:a:10*pa:10&a:f86(hex)pa:f86(hex)&pa:f88(hex)…...…...f86f8af8cf8b整型变量a10指针变量paf87f88f89f86Eval
uationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slid
esfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.例输入两个数,并使其从大到小输出main(){int*p1,*p2,*p,a,b;scanf("%d,%d",&a,&b);p1=&a;p2=&b;if(a<b)
{p=p1;p1=p2;p2=p;}printf("a=%d,b=%d\n",a,b);printf("max=%d,min=%d\n",*p1,*p2);}运行结果:a=5,b=9max=9,min=5…...…...指针变量p1指
针变量p20002008200220042006指针变量p2整型变量b整型变量a5200692008200620082006Evaluationonly.eatedwithAspose.Slidesfor.NET3.5Cl
ientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright
2004-2011AsposePtyLtd.指针变量作为函数参数——地址传递特点:共享内存,“双向”传递swap(intx,inty){inttemp;temp=x;x=y;y=temp;}main(){inta,b;scanf("%d,%d",&a,&b);if(a<b)swap(a
,b);printf("\n%d,%d\n",a,b);}例将数从大到小输出…...…...20002008200A2002200420065变量a变量b(main)9变量temp变量y变量x(swap)5
5959COPYEvaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwit
hAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.指针变量作为函数参数——地址传递特点:共享内存,“双向”传递swap(i
ntx,inty){inttemp;temp=x;x=y;y=temp;}main(){inta,b;scanf("%d,%d",&a,&b);if(a<b)swap(a,b);printf("\n%d,%d\n",a,b);}例将数从大到小输出值传递….
..…...20002008200A2002200420065变量a变量b(main)9运行结果:5,9Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copy
right2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.swap(in
t*p1,int*p2){intp;p=*p1;*p1=*p2;*p2=p;}main(){inta,b;int*pointer_1,*pointer_2;scanf("%d,%d",&a,&b);pointer_1=
&a;pointer_2=&b;if(a<b)swap(pointer_1,pointer_2);printf("\n%d,%d\n",a,b);}…...20002008200A200220042006200C200E2010...59整型变量a整型变量b(main)指针pointer_1指针p
ointer_220002002(swap)指针p1指针p2整型p5920002002COPY5例将数从大到小输出Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2
011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.swap(int*p1,
int*p2){intp;p=*p1;*p1=*p2;*p2=p;}main(){inta,b;int*pointer_1,*pointer_2;scanf("%d,%d",&a,&b);pointer_1=&a;pointer_2=&b;if(a<b)swap(pointer_
1,pointer_2);printf("\n%d,%d\n",a,b);}…...20002008200A200220042006200C200E2010...59整型变量a整型变量b(main)指针pointer
_1指针pointer_22000200259例将数从大到小输出运行结果:9,5地址传递Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011Asp
osePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyL
td.swap(int*p1,int*p2){int*p;*p=*p1;*p1=*p2;*p2=*p;}main(){inta,b;int*pointer_1,*pointer_2;scanf("%d,%d",&a,&b);pointer_1=&a;pointer
_2=&b;if(a<b)swap(pointer_1,pointer_2);printf("\n%d,%d\n",a,b);}运行结果:9,9编译警告!结果不对!intx;int*p=&x;x;例将数从大到小输出…...20002008200A2002
20042006200C200E2010...59整型变量a整型变量b(main)指针pointer_1指针pointer_2200020029920002002COPY(swap)指针p1指针p2指针p****假设2000指针变量在使用前必须
赋值!Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Sl
idesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd./*ch9_32.c*/swap(intx,inty){intt;t=x;x=y;y=
t;}main(){inta,b;int*pointer_1,*pointer_2;scanf("%d,%d",&a,&b);pointer_1=&a;pointer_2=&b;if(a<b)swap(*pointer_1,*pointer_2
);printf("\n%d,%d\n",a,b);}运行结果:5,9例将数从大到小输出值传递…...20002008200A200220042006200C200E2010...59整型a整型b(main)pointer_1poi
nter_2200020029COPY(swap)整型x整型b整型t5559Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright20
04-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePt
yLtd.运行结果:5,9例将数从大到小输出swap(int*p1,int*p2){int*p;p=p1;p1=p2;p2=p;}main(){inta,b;int*pointer_1,*pointer_2;scanf("%d,%d",&a,&b);pointer_1=&a;p
ointer_2=&b;if(a<b)swap(pointer_1,pointer_2);printf("%d,%d",*pointer_1,*pointer_2);}…...20002008200A20022004200
6200C200E2010...59整型a整型b(main)pointer_1pointer_22000200220002002COPY(swap)指针p1指针p2指针p****2000地址传递20002002Evaluationonly.eatedwithAspose.
Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Cop
yright2004-2011AsposePtyLtd.§8.3指针与数组指向数组元素的指针变量例intarray[10];int*p;p=&array[0];//p=array;或int*p=&array[0];或i
nt*p=array;array[0]array[1]array[2]array[3]array[9]...整型指针p&array[0]p数组名是表示数组首地址的地址常量Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.
2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyr
ight2004-2011AsposePtyLtd.指针的运算指针变量的赋值运算p=&a;(将变量a地址p)p=array;(将数组array首地址p)p=&array[i];(将数组元素地址p)
p1=p2;(指针变量p2值p1)不能把一个整数p,也不能把p的值整型变量如inti,*p;p=1000;()i=p;()指针变量与其指向的变量具有相同数据类型Evaluationonly.eatedwithAspose.
Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProf
ile5.2.0Copyright2004-2011AsposePtyLtd.指针的算术运算:pipid(i为整型数,d为p指向的变量所占字节数)p++,p--,p+i,p-i,p+=i,p-=i等若p1与p2指向同一数组,p1-p2=两指针间元素个数(p1-p2)/dp1
+p2无意义例p指向float数,则p+1p+14例p指向int型数组,且p=&a[0];则p+1指向a[1]例inta[10];int*p=&a[2];p++;*p=1;例inta[10];int*p1=&a[2];int*p2=&a[5];则:p2-p1=3;a[0]a[1
]a[2]a[3]a[4]a[5]a[6]a[7]a[8]a[9]a数组pp+1,a+1p+i,a+ip+9,a+91Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfil
e5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.指针变量的
关系运算若p1和p2指向同一数组,则p1<p2表示p1指的元素在前p1>p2表示p1指的元素在后p1==p2表示p1与p2指向同一元素若p1与p2不指向同一数组,比较无意义p==NULL或p!=NULLEvaluationonly.eatedwithAspose.Slid
esfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copy
right2004-2011AsposePtyLtd.数组元素表示方法a[0]a[1]a[2]a[3]a[9]...aa+9a+1a+2地址元素下标法a[0]a[1]a[2]a[9]a[0]a[1]a[2]a[3]a[9]...pp+9p+1
p+2地址元素指针法*p*(p+1)*(p+2)*(p+9)[]变址运算符a[i]*(a+i)a[i]p[i]*(p+i)*(a+i)*a*(a+1)*(a+2)*(a+9)p[0]p[1]p[2]p[9]Evaluationon
ly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5Cli
entProfile5.2.0Copyright2004-2011AsposePtyLtd.a[0]a[1]a[2]a[3]a[4]例数组元素的引用方法main(){inta[5],*pa,i;for(i=0;i<5;i
++)a[i]=i+1;pa=a;for(i=0;i<5;i++)printf("*(pa+%d):%d\n",i,*(pa+i));for(i=0;i<5;i++)printf("*(a+%d):%d\n",i,*
(a+i));for(i=0;i<5;i++)printf("pa[%d]:%d\n",i,pa[i]);for(i=0;i<5;i++)printf("a[%d]:%d\n",i,a[i]);}12345paEvaluationonly.eatedwithAspose.
Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5
ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.例inta[]={1,2,3,4,5,6,7,8,9,10},*p=a,i;数组元素地址的正确表示:(A)&(a+1)(B)a++(C
)&p(D)&p[i]数组名是地址常量p++,p--()a++,a--()a+1,*(a+2)()Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.
2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright20
04-2011AsposePtyLtd.例voidmain(){inta[]={5,8,7,6,2,7,3};inty,*p=&a[1];y=(*--p)++;printf(“%d”,y);printf(“%d”,a[0]);}输出:56pp58762730123456a例注意指针变
量的运算6Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.
NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.main(){inti,*p,a[7];p=a;for(i=0;i<7;i++)scanf("%d",
p++);printf("\n");for(i=0;i<7;i++,p++)printf("%d",*p);}例注意指针的当前值p=a;pp58762730123456apppppp指针变量可以指到数组后的内
存单元Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Sl
idesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.数组名作函数参数数组名作函数参数,是地址传递数组名作函数参数,实参与形参的对应关系实参形参数组名
指针变量数组名指针变量数组名数组名指针变量指针变量Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluat
iononly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.例将数组a中的n个整数按相反
顺序存放ij379110675420123456789ijijijji11760594723实参与形参均用数组voidinv(intx[],intn){intt,i,j,m=(n-1)/2;for(i=0;i<=m;i++){j=
n-1-i;t=x[i];x[i]=x[j];x[j]=t;}}main(){inti,a[10]={3,7,9,11,0,6,7,5,4,2};inv(a,10);printf("Thearrayhasbeenreverted:\n");fo
r(i=0;i<10;i++)printf("%d,",a[i]);printf("\n");}m=4Evaluationonly.eatedwithAspose.Slidesfor.NET3.5Clie
ntProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.例将数
组a中的n个整数按相反顺序存放voidinv(int*x,intn){intt,*p,*i,*j,m=(n-1)/2;i=x;j=x+n-1;p=x+m;for(;i<=p;i++,j--){t=*i;*i=*j;*j=t;}}main(){inti,a[10
]={3,7,9,11,0,6,7,5,4,2};inv(a,10);printf("Thearrayhasbeenreverted:\n");for(i=0;i<10;i++)printf("%d,",a[i]);printf("\n");}�实参用数组,形参用指针变量37911
067542a[0]a[1]a[2]a[3]a[4]a[5]a[6]a[7]a[8]a[9]xp=x+ma数组60711594723ijijijjijiEvaluationonly.eatedwithAspos
e.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright
2004-2011AsposePtyLtd.例将数组a中的n个整数按相反顺序存放voidinv(int*x,intn){intt,*i,*j,*p,m=(n-1)/2;i=x;j=x+n-1;p=x+m;for(;i<=p;i++,j--){t=*i;*i=*j;*j=t;}}mai
n(){inti,a[10],*p=a;for(i=0;i<10;i++,p++)scanf("%d",p);p=a;inv(p,10);printf("Thearrayhasbeenreverted:\n");for(p=a;p<a+10;p++)printf(
"%d",*p);}�实参与形参均用指针变量Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePty
Ltd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.例将数组a中的n个整数按相反顺序存放voidinv(intx[],intn){
intt,i,j,m=(n-1)/2;for(i=0;i<=m;i++){j=n-1-i;t=x[i];x[i]=x[j];x[j]=t;}}main(){inti,a[10],*p=a;for(i=0;i<10;i++,p++)scanf("%d",p);p=a;inv(p,10
);printf("Thearrayhasbeenreverted:\n");for(p=arr;p<arr+10;p++)printf("%d",*p);}�实参用指针变量,形参用数组Evaluationonly.eatedwithAspose.Slidesfor.NET3.5Cl
ientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011Aspose
PtyLtd.一级指针变量与一维数组的关系int*p与intq[10]数组名是指针(地址)常量p=q;p+i是q[i]的地址数组元素的表示方法:下标法和指针法,即若p=q,则p[i]q[i]*(p+i)
*(q+i)形参数组实质上是指针变量,即intq[]int*q在定义指针变量(不是形参)时,不能把int*p写成intp[];系统只给p分配能保存一个指针值的内存区(一般2字节);而给q分配2*10字节的内存区Evaluationonly.eatedwithAspose
.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5Cli
entProfile5.2.0Copyright2004-2011AsposePtyLtd.指针与二维数组二维数组的地址对于一维数组:(1)数组名array表示数组的首地址,即array[0]的地址;(2)数组名array是地址常量(3)array+i是元素
array[i]的地址(4)array[i]*(array+i)arrayintarray[10];Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2
004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.对于二维数组:(1)a是数组名,包含三个元素a[0],a[1],
a[2](2)每个元素a[i]又是一个一维数组,包含4个元素aa+1a+2*(*(a+0)+1)*(a[0]+1)inta[3][4];a[0]a[1]a[2]2000200820162000200220082010201
62018a[0][0]a[0][1]a[1][0]a[1][1]a[2][0]a[2][1]a[0][2]a[0][3]a[1][2]a[1][3]a[2][2]a[2][3]基类型行指针与列指针a[0
]+1a[1]+1a[2]+1*(a+0)+1*(a+1)+1*(a+2)+1Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evalu
ationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.对二维数组inta[3][4],有a-----二维数组的首地址,即第0行的
首地址a+i-----第i行的首地址a[i]*(a+i)------第i行第0列的元素地址a[i]+j*(a+i)+j-----第i行第j列的元素地址*(a[i]+j)*(*(a+i)+j)a[i][j]a+i=&a[i]=a[i]=*(a+i)=&a[i][0]
,值相等,含义不同a+i&a[i],表示第i行首地址,指向行a[i]*(a+i)&a[i][0],表示第i行第0列元素地址,指向列inta[3][4];a[0]a[1]a[2]2000200820162000
20022008201020162018a[0][0]a[0][1]a[1][0]a[1][1]a[2][0]a[2][1]a[0][2]a[0][3]a[1][2]a[1][3]a[2][2]a[2][3]aa
+1a+2Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Eval
uationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.inta[3][4];a[0][0]a[0][
1]a[1][0]a[1][1]a[2][0]a[2][1]a[0][2]a[0][3]a[1][2]a[1][3]a[2][2]a[2][3]二维数组元素表示形式:(1)a[1][2](2)*(a[1]+2)(3)*(*(a+1)+2)(4)*(&a[0][0
]+1*4+2)地址表示:(1)a+1(2)&a[1][0](3)a[1](4)*(a+1)(5)(int*)(a+1)行指针列指针地址表示:(1)&a[1][2](2)a[1]+2(3)*(a+1)+2(4)&a[0][0]+1*4+2Evaluationonly.eatedwithAspo
se.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright20
04-2011AsposePtyLtd.表示形式含义地址a二维数组名,数组首地址a[0],*(a+0),*a第0行第0列元素地址a+1第1行首地址a[1],*(a+1)第1行第0列元素地址a[1]+2,*(a+
1)+2,&a[1][2]第1行第2列元素地址*(a[1]+2),*(*(a+1)+2),a[1][2]第1行第2列元素值2000200020082008201213Evaluationonly.eatedwithAsp
ose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0
Copyright2004-2011AsposePtyLtd.二维数组的指针变量指向二维数组元素的指针变量例指向二维数组元素的指针变量main(){staticinta[3][4]={1,3,5,7,9,11,13,15,17,19,21,23};in
t*p;for(p=a[0];p<a[0]+12;p++){if((p-a[0])%4==0)printf("\n");printf("%4d",*p);}}p=*a;p=&a[0][0];p=*(a+0);p=a;p=
*a;p=&a[0][0];p=(int*)a;p=a;inta[3][4];a[0][0]a[0][1]a[1][0]a[1][1]a[2][0]a[2][1]a[0][2]a[0][3]a[1][2]a[
1][3]a[2][2]a[2][3]pEvaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluation
only.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.指向一维数组的指针变量定义形式:数据类型(*指针名)[一维数组维数];例
int(*p)[4];()不能少int(*p)[4]与int*p[4]不同p的值是一维数组的首地址,p是行指针可让p指向二维数组某一行如inta[3][4],(*p)[4]=a;inta[3][4];a[0][0]a[0][1]a[1][0]a[1][1]a[2][0]a[2][1]a
[0][2]a[0][3]a[1][2]a[1][3]a[2][2]a[2][3]aa+1a+2pp+1p+2p[0]+1或*p+1p[1]+2或*(p+1)+2*(*p+1)或(*p)[1]*(*(p+1)+2)一维数组指针变量维数和二维数组列数必须相同Evaluationonly
.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.
0Copyright2004-2011AsposePtyLtd.例一维数组指针变量举例main(){staticinta[3][4]={1,3,5,7,9,11,13,15,17,19,21,23};inti,j,(*p)[4];for(p=a,i=0;i<3;i++,p++)for
(j=0;j<4;j++)printf("%d",*(*p+j));printf("\n");}p=a[0];p=*a;p=&a[0][0];p=&a[0];p=a[0];p=*a;p=&a[0][0];p=&a[0];inta[3][4];a[0]
[0]a[0][1]a[1][0]a[1][1]a[2][0]a[2][1]a[0][2]a[0][3]a[1][2]a[1][3]a[2][2]a[2][3]pppp[0][j]Evaluationonly.eatedwithA
spose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile
5.2.0Copyright2004-2011AsposePtyLtd.例二维数组与指针运算main(){inta[3][4]={{1,2,3,4},{3,4,5,6},{5,6,7,8}};inti;int(*p)[4]=a,*q=a[0];f
or(i=0;i<3;i++){if(i==0)(*p)[i+i/2]=*q+1;elsep++,++q;}for(i=0;i<3;i++)printf("%d,",a[i][i]);printf("%d,%d\n",*((int*)p),*q);}运行结果:2,4,7,
5,3123434565678pq2pqpqEvaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithA
spose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.二维数组的指针作函数参数用指向变量的指针变量用指向一
维数组的指针变量用二维数组名实参形参数组名intx[][4]指针变量int(*q)[4]数组名intx[][4]指针变量int(*q)[4]数组名a数组名a指针变量p1指针变量p1若inta[3][4];int(*p1)[4]=a;int*p2=a[0];指针变量p2指针变
量int*qEvaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLt
d.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.例3个学生各学4门课,计算总平均分,并输出第n个学生成绩main(){voidaverage(
float*p,intn);voidsearch(float(*p)[4],intn);floatscore[3][4]={{65,67,79,60},{80,87,90,81},{90,99,100,98}};average(*score,12);search(score,2);}voidave
rage(float*p,intn){float*p_end,sum=0,aver;p_end=p+n-1;for(;p<=p_end;p++)sum=sum+(*p);aver=sum/n;printf("average=%5.
2f\n",aver);}voidsearch(float(*p)[4],intn){inti;printf("No.%d:\n",n);for(i=0;i<4;i++)printf("%5.2f",*(*(p+n)+i
));}列指针行指针函数说明floatp[][4]6552796080879081909910098ppp[n][i]Evaluationonly.eatedwithAspose.Slidesfor.NET3.5Cl
ientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Cop
yright2004-2011AsposePtyLtd.例3个学生各学4门课,计算总平均分,并查找一门以上课不及格学生,输出其各门课成绩voidsearch(float(*p)[4],intn){inti,j,flag;for(j=0;j<n;j++){flag=0;for(i=0;i<4
;i++)if(*(*(p+j)+i)<60)flag=1;if(flag==1){printf("No.%disfail,hisscoresare:\n",j+1);for(i=0;i<4;i++)
printf("%5.1f",*(*(p+j)+i));printf("\n");}}}main(){voidsearch(float(*p)[4],intn);floatscore[3][4]={{...},{...}
,{...}};search(score,3);}6552796080879081909910098pp[j][i]Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientP
rofile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePty
Ltd.二维数组与一维数组指针变量的关系如inta[5][10]与int(*p)[10];二维数组名是一个指向有10个元素的一维数组的指针常量p=a+i使p指向二维数组的第i行*(*(p+i)
+j)a[i][j]二维数组形参实际上是一维数组指针变量,即intx[][10]int(*x)[10]变量定义(不是形参)时两者不等价系统只给p分配能保存一个指针值的内存区(一般2字节);而给a分配2*5*10字节的内存区Evaluationonly.
eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5
ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.§8.4指针与字符串字符串表示形式用字符数组实现例main(){charstring[]=“IloveChina!”;printf(“%s\n”,string);printf(“%s\n
”,string+7);}IloveChistring[0]string[1]string[2]string[3]string[4]string[5]string[6]string[7]string[8]
string[9]stringstring[10]string[11]string[12]string[13]n!a\0Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2
.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.用字符指针实现例ma
in(){char*string=“IloveChina!”;printf(“%s\n”,string);string+=7;while(*string){putchar(string[0]);string++;}}
IloveChistringn!a\0字符指针初始化:把字符串首地址赋给stringchar*string;string=“IloveChina!”;string*string!=0Evaluationonly.eatedwithA
spose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5Client
Profile5.2.0Copyright2004-2011AsposePtyLtd.字符串指针作函数参数例用函数调用实现字符串复制(1)用字符数组作参数(2)用字符指针变量作参数aIamateaceh\0r.fromabyua
rasutndetoboet.\0Iaaeceh\0r.t.\0mtavoidcopy_string(charfrom[],charto[]){inti=0;while(from[i]!='\0'){to[i]=from[i];i++;}to[i]='\0';}main(){char
a[]="Iamateacher.";charb[]="Youareastudent.";printf("string_a=%s\nstring_b=%s\n",a,b);copy_string(a,b);printf("\
nstring_a=%s\nstring_b=%s\n",a,b);}voidcopy_string(char*from,char*to){for(;*from!='\0';from++,to++)*to=*from;*t
o='\0';}main(){char*a="Iamateacher.";char*b="Youareastudent.";printf("string_a=%s\nstring_b=%s\n",a,b);co
py_string(a,b);printf("\nstring_a=%s\nstring_b=%s\n",a,b);}Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0
Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.字符指针变量与字符
数组char*cp;与charstr[20];str由若干元素组成,每个元素放一个字符;而cp中存放字符串首地址charstr[20];str=“IloveChina!”;()char*cp;cp=“Ilov
eChina!”;()str是地址常量;cp是地址变量cp接受键入字符串时,必须先开辟存储空间例charstr[10];scanf(“%s”,str);()而char*cp;scanf(“%s”,cp);()改为:char*cp,str[10];cp=st
r;scanf(“%s”,cp);()Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspo
se.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.字符串与数组关系字符串用一维字符数组存放字符数组具有一维数组的所有特点数组名是指向数组首地址的地址常
量数组元素的引用方法可用指针法和下标法数组名作函数参数是地址传递等区别存储格式:字符串结束标志赋值方式与初始化输入输出方式:%s%ccharstr[]={“Hello!”};()charstr[]=“Hello!”;()char
str[]={„H‟,„e‟,„l‟,„l‟,„o‟,„!‟};()char*cp=“Hello”;()inta[]={1,2,3,4,5};()int*p={1,2,3,4,5};()charstr[10],
*cp;inta[10],*p;str=“Hello”;()cp=“Hello!”;()a={1,2,3,4,5};()p={1,2,3,4,5};()scanf(“%s”,str);printf(“%s”,str)
;gets(str);puts(str);Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-20
11AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.§8.5指针与函数函数指针:函数在编译时
被分配的入口地址,用函数名表示max…...指令1指令2函数指针变量赋值:如p=max;函数返回值的数据类型专门存放函数入口地址可指向返回值类型相同的不同函数指向函数的指针变量定义形式:数据类型(*指针变量名)();如int(*p)();函数指针变量指向的函数必须有函
数说明函数调用形式:c=max(a,b);c=(*p)(a,b);c=p(a,b);对函数指针变量pn,p++,p--无意义()不能省int(*p)()与int*p()不同Evaluationonly.eatedwit
hAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.
2.0Copyright2004-2011AsposePtyLtd.例用函数指针变量调用函数,比较两个数大小main(){intmax(int,int);inta,b,c;scanf("%d,%d",&a,&b);c=max(a,b);printf("a=%d,b=%d,max=%d\n
",a,b,c);}intmax(intx,inty){intz;if(x>y)z=x;elsez=y;return(z);}main(){intmax(int,int),(*p)();inta,b,c;p=max;scanf("%d,%d",&a,&b);c=(*p)(a,b);
printf("a=%d,b=%d,max=%d\n",a,b,c);}intmax(intx,inty){intz;if(x>y)z=x;elsez=y;return(z);}Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfil
e5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2
011AsposePtyLtd.用函数指针变量作函数参数例用函数指针变量作参数,求最大值、最小值和两数之和voidmain(){inta,b,max(int,int),min(int,int),add(int,int);voidprocess(int,int,int(*fun)(
));scanf("%d,%d",&a,&b);process(a,b,max);process(a,b,min);process(a,b,add);}voidprocess(intx,inty,int(*f
un)()){intresult;result=(*fun)(x,y);printf("%d\n",result);}max(intx,inty){printf(“max=”);return(x>y?x:y);}min(intx,inty){printf(“mi
n=”);return(x<y?x:y);}add(intx,inty){printf(“sum=”);return(x+y);}Evaluationonly.eatedwithAspose.Slidesfor.NET3.5Cl
ientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011
AsposePtyLtd.§8.6返回指针值的函数函数定义形式:类型标识符*函数名(参数表);例int*f(intx,inty)例指针函数实现:有若干学生成绩,要求输入学生序号后,能输出其全部成绩main(){floatscore[][4]={{60,70,80,90},{56,89,67,
88},{34,78,90,66}};float*search(float(*pointer)[4],intn),*p;inti,m;printf("Enterthenumberofstudent:");scanf("%d",&m);printf("Thescores
ofNo.%dare:\n",m);p=search(score,m);for(i=0;i<4;i++)printf("%5.2f\t",*(p+i));}float*search(float(*pointer
)[4],intn){float*pt;pt=*(pointer+n);return(pt);}pointerpointer+1347890665689678860708090score数组ppppEvalu
ationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithA
spose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.例写一个函数,求两个int型变量中居于较大值的变量的地址int*f1(int*x,int*y){if(*x>*y)re
turnx;elsereturny;}main(){inta=2,b=3;int*p;p=f1(&a,&b);printf("%d\n",*p);}…...20002008200A2002200420
0623指针变量y指针变量x(f1)20022000COPY变量a变量b(main)指针变量p**Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright20
04-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.例写一个函数,求两个int型变
量中居于较大值的变量的地址…...…...20002008200A2002200420062变量a变量b(main)3指针变量p**2002int*f3(int*x,int*y){if(*x>*y)returnx;elsereturny;}main(){inta=2,b=3;i
nt*p;p=f1(&a,&b);printf("%d\n",*p);}Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011Aspos
ePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.例写一个函数,求两个int型变量中居于较大值的变量的地址int*f3(int
x,inty){if(x>y)return&x;elsereturn&y;}main(){inta=2,b=3;int*p;p=f3(a,b);printf("%d\n",*p);}…...20002008200A20022004200623变量y变量x(f3)32COPY变量a变量b(mai
n)指针变量p**Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Eva
luationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.例写一个函数,求两个int型变量中居于较大值的变量的地址不能返回形参或局部变
量的地址作函数返回值…...…...20002008200A2002200420062变量a变量b(main)3指针变量p**200Aint*f3(intx,inty){if(x>y)return&x;elsereturn&y;}main(){inta=2,b=3;int*p;p=
f3(a,b);printf("%d\n",*p);}Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Ev
aluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.§8.7指针数组和多级指针用于处理二维数组或多个字符串
指针数组定义:数组中的元素为指针变量定义形式:[存储类型]数据类型*数组名[数组长度说明];例int*p[4];指针所指向变量的数据类型指针本身的存储类型区分int*p[4]与int(*p)[4]指针数组赋值与初始化赋值:main(
){intb[2][3],*pb[2];pb[0]=b[0];pb[1]=b[1];……..}int*pb[2]pb[0]pb[1]intb[2][3]123246初始化:main(){intb[2][3],*pb[]=
{b[0],b[1]};……..}int*pb[2]pb[0]pb[1]intb[2][3]123246Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientPr
ofile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile
5.2.0Copyright2004-2011AsposePtyLtd.指针数组赋值与初始化Lisp\0Fortran\0Basic\0p[0]p[1]p[2]p[3]0赋值:main(){chara[]="Fortran";charb[
]="Lisp";charc[]="Basic";char*p[4];p[0]=a;p[1]=b;p[2]=c;p[3]=NULL;……..}或:main(){char*p[4];p[0]="Fortran";p[1]="Lisp";p[2]="Basic";p[3]=N
ULL;……..}初始化:main(){char*p[]={"Fortran","Lisp","Basic",NULL};……..}Lisp\0Fortran\0Basic\0p[0]p[1]p[2]
p[3]0Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedw
ithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.charname[5][9]={“gain”,“much”,“stron
ger”,“point”,“bye”};char*name[5]={“gain”,“much”,“stronger”,“point”,“bye”};gain\0stronger\0point\0much\0name[0]name[1]name[2]name[3]name[4]bye\
0gain\0stronger\0point\0much\0bye\0二维数组与指针数组区别:二维数组存储空间固定字符指针数组相当于可变列长的二维数组分配内存单元=数组维数*2+各字符串长度指针数组元素的作用相当于二维数组的行
名但指针数组中元素是指针变量二维数组的行名是地址常量Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011Aspose
PtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.main(){intb[2][3],*pb[2];
inti,j;for(i=0;i<2;i++)for(j=0;j<3;j++)b[i][j]=(i+1)*(j+1);pb[0]=b[0];pb[1]=b[1];for(i=0;i<2;i++)for(j=0;j<3;j++,pb[i]++)printf("b[%d][%d]:
%2d\n",i,j,*pb[i]);}例用指针数组处理二维数组int*pb[2]pb[0]pb[1]intb[2][3]b[0][0]*pb[0]b[0][1]*(pb[0]+1)b[0][2]*(pb[0]+2)b[1][0]*pb[1]b[1][1]*(pb[1]+1)b[1][2]*(
pb[1]+2)123246Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Sli
desfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.例对字符串排序(简单选择排序)main(){voidsort(char*name[],intn
),print(char*name[],intn);char*name[]={"Followme","BASIC","GreatWall","FORTRAN","Computer"};intn=5;sort(name,n);print(name,n)
;}voidsort(char*name[],intn){char*temp;inti,j,k;for(i=0;i<n-1;i++){k=i;for(j=i+1;j<n;j++)if(strcmp(name[k],name[j])>0)k=j;if
(k!=i){temp=name[i];name[i]=name[k];name[k]=temp;}}}name[0]name[1]name[2]name[3]name[4]nameGreatWallFORTRANComputerFollowme
BASICkjkjjji=0Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAsp
ose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.例对字符串排序(简单选择排序)main(){voidsort(char*name[],intn),print(char*name
[],intn);char*name[]={"Followme","BASIC","GreatWall","FORTRAN","Computer"};intn=5;sort(name,n);print(name,n);}voidsort(char*name[],intn){char*
temp;inti,j,k;for(i=0;i<n-1;i++){k=i;for(j=i+1;j<n;j++)if(strcmp(name[k],name[j])>0)k=j;if(k!=i){temp=name[i];name[i]=name
[k];name[k]=temp;}}}name[0]name[1]name[2]name[3]name[4]nameGreatWallFORTRANComputerFollowmeBASICkkjjji=1kEvaluationonly.eatedwi
thAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright
2004-2011AsposePtyLtd.例对字符串排序(简单选择排序)main(){voidsort(char*name[],intn),print(char*name[],intn);char*name[]={"Followme","BAS
IC","GreatWall","FORTRAN","Computer"};intn=5;sort(name,n);print(name,n);}voidsort(char*name[],intn){char*tem
p;inti,j,k;for(i=0;i<n-1;i++){k=i;for(j=i+1;j<n;j++)if(strcmp(name[k],name[j])>0)k=j;if(k!=i){temp=name[i];name[i
]=name[k];name[k]=temp;}}}name[0]name[1]name[2]name[3]name[4]nameGreatWallFORTRANComputerFollowmeBASICkkjji=2Eva
luationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5C
lientProfile5.2.0Copyright2004-2011AsposePtyLtd.例对字符串排序(简单选择排序)main(){voidsort(char*name[],intn),print(char*name[],intn);ch
ar*name[]={"Followme","BASIC","GreatWall","FORTRAN","Computer"};intn=5;sort(name,n);print(name,n);}voidsort(char*name[],intn){char*temp;inti,
j,k;for(i=0;i<n-1;i++){k=i;for(j=i+1;j<n;j++)if(strcmp(name[k],name[j])>0)k=j;if(k!=i){temp=name[i];name[i]=name[k];name[k
]=temp;}}}name[0]name[1]name[2]name[3]name[4]nameGreatWallFORTRANComputerFollowmeBASICkkji=3Evaluationonly.eatedwithAspose.Slidesfor.NET3.5Clie
ntProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProf
ile5.2.0Copyright2004-2011AsposePtyLtd.例对字符串排序(简单选择排序)main(){voidsort(char*name[],intn),print(char*name[],intn);char*name
[]={"Followme","BASIC","GreatWall","FORTRAN","Computer"};intn=5;sort(name,n);print(name,n);}voidsort(char*name[],intn){char*temp;inti,j,k;fo
r(i=0;i<n-1;i++){k=i;for(j=i+1;j<n;j++)if(strcmp(name[k],name[j])>0)k=j;if(k!=i){temp=name[i];name[i]=name[k];name[k]
=temp;}}}name[0]name[1]name[2]name[3]name[4]nameGreatWallFORTRANComputerFollowmeBASICEvaluationonly.eatedwithAspose.Slide
sfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor
.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.多级指针定义:指向指针的指针一级指针:指针变量中存放目标变量的地址p1&p2&i3P2(指针变量)i(整型变量)例int**p1;int*p2;inti=3;p2=&i;p1=
&p2;**p1=5;二级指针:指针变量中存放一级指针变量的地址例int*p;inti=3;p=&i;*p=5;&i3P(指针变量)i(整型变量)一级指针单级间接寻址二级指针一级指针目标变量二级间接寻址Evaluationonly.eatedwithA
spose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0
Copyright2004-2011AsposePtyLtd.定义形式:[存储类型]数据类型**指针名;如char**p;例inti,**p;p=&i;()//p是二级指针,不能用变量地址为其赋值指针本身的存储类型最终目标变量的数据类型*p是p间接指向对象的地址**p是p
间接指向对象的值例inti=3;int*p1;int**p2;p1=&i;p2=&p1;**p=5;ip1p23&i&p1**p2,*p1*p2多级指针例三级指针int***p;四级指针char****p;Ev
aluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5Clien
tProfile5.2.0Copyright2004-2011AsposePtyLtd.20002008200A20022004200612变量a变量b(main)指针变量p2000指针变量q2002例一级指针与
二级指针#include<stdio.h>voidswap(int*r,int*s){int*t;t=r;r=s;s=t;}main(){inta=1,b=2,*p,*q;p=&a;q=&b;swap(p,
q);printf("%d,%d\n",*p,*q);}20022000COPY指针变量s指针变量r(swap)指针变量t200020022000Evaluationonly.eatedwithAspose.Slidesfor.NET3.5Clie
ntProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.
2.0Copyright2004-2011AsposePtyLtd.20002008200A20022004200612变量a变量b(main)指针变量p2000指针变量q2002例一级指针与二级指针#include<stdio.h>voidswap(int*r,int*s){int*t;t=r;
r=s;s=t;}main(){inta=1,b=2,*p,*q;p=&a;q=&b;swap(p,q);printf("%d,%d\n",*p,*q);}输出:1,2Evaluationonly.eatedwithAspose.Slidesfor.NE
T3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfil
e5.2.0Copyright2004-2011AsposePtyLtd.例一级指针与二级指针#include<stdio.h>voidswap(int*r,int*s){int*t;t=r;r=s;
s=t;}main(){inta=1,b=2,*p,*q;p=&a;q=&b;swap(p,q);printf("%d,%d\n",*p,*q);}abpqabpqrsabpqsrabpq输出:1,2Evaluationonly.eatedwithAspose.Slides
for.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Co
pyright2004-2011AsposePtyLtd.例一级指针与二级指针#include<stdio.h>voidswap(int**r,int**s){int*t;t=*r;*r=*s;*s=t;}main(){inta=1,b=2,*p,*q;p=&a;q=&b;swap(&
p,&q);printf("%d,%d\n",*p,*q);}20002008200A20022004200612变量a变量b(main)指针变量p2000指针变量q200220062004COPY二级指针s二级指针r(swap)指针变量t200020022000Evaluationonly.ea
tedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Sl
idesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.例一级指针与二级指针#include<stdio.h>voidswap(int**r,int**s){int*t;t=*r;*r=*s;*s=t;}main()
{inta=1,b=2,*p,*q;p=&a;q=&b;swap(&p,&q);printf("%d,%d\n",*p,*q);}20002008200A20022004200612变量a变量b(main)指针变量p2000指针变量q20
0220002002输出:2,1Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.E
valuationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.例一级指针与二级指针#include<stdio.h>voidswap(int**
r,int**s){int*t;t=*r;*r=*s;*s=t;}main(){inta=1,b=2,*p,*q;p=&a;q=&b;swap(&p,&q);printf("%d,%d\n",*p,*q);}abpqbapqabrsp
qabrspq输出:2,1Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Sli
desfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.例用二级指针处理字符串#defineNULL0voidmain(){char**p;char*na
me[]={"hello","good","world","bye",""};p=name+1;printf("%o:%s",*p,*p);p+=2;while(**p!=NULL)printf("%s\n",*p++);}name[0]name[1]name[2]name[
3]name[4]char*name[5]worldbye\0hellogoodnamep运行结果:644:goodbye用*p可输出地址(%o或%x),也可用它输出字符串(%s)p*(p++)Evalu
ationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5Clien
tProfile5.2.0Copyright2004-2011AsposePtyLtd.二级指针与指针数组的关系int**p与int*q[10]指针数组名是二级指针常量p=q;p+i是q[i]的地址指针数组作形参,int*q[]与int**q完全等价;但作为变量定义两者不同系统只给p分配
能保存一个指针值的内存区;而给q分配10块内存区,每块可保存一个指针值Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright20
04-2011AsposePtyLtd.Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLt
d.命令行参数命令行:在操作系统状态下,为执行某个程序而键入的一行字符命令行一般形式:命令名参数1参数2………参数nmain(intargc,char*argv[]){………}命令行参数传递带参
数的main函数形式:C:\TC>copy[.exe]source.ctemp.c有3个字符串参数的命令行命令行中参数个数元素指向命令行参数中各字符串首地址形参名任意命令行实参main(形参)系统自动调用main函数时传递第一个参数:main所在的可
执行文件名Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly
.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.例输出命令行参数/*test.c*/main(intargc,char*argv
[]){while(argc>1){++argv;printf("%s\n",*argv);--argc;}}main(intargc,char*argv[]){while(argc-->0)printf("%s\n",*argv++);}1.编译、链接test.
c,生成可执行文件test.exe2.在DOS状态下运行(test.exe所在路径下)例如:C:\TC>test[.exe]helloworld!运行结果:helloworld!运行结果:testhelloworld!argv[0]argv[1]argv[2]char*argv[]world
testhelloargvargc=3Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eatedwith
Aspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.定义含义inti;int*p;inta[n];int*p[n];int(*p)[n];intf();int*p();int(*p
)();int**p;定义整型变量ip为指向整型数据的指针变量定义含n个元素的整型数组an个指向整型数据的指针变量组成的指针数组pp为指向含n个元素的一维整型数组的指针变量f为返回整型数的函数p为返回指针的函数,该指针指向一个整型数据p为指向函数的指针变量,该函数返回整
型数p为指针变量,它指向一个指向整型数据的指针变量指针的数据类型Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Evaluationonly.eate
dwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.例下列定义的含义(1)int*p[3];(2)int(*p)[3];(3
)int*p(int);(4)int(*p)(int);(5)int*(*p)(int);(6)int(*p[3])(int);(7)int*(*p[3])(int);函数指针数组,函数返回int型指针指针数组指向一维数组的指针返回指针的函数指向函数的指针,函数返回in
t型变量指向函数的指针,函数返回int型指针函数指针数组,函数返回int型变量Evaluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.Ev
aluationonly.eatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0Copyright2004-2011AsposePtyLtd.