黑马程序员--C语言-指针
来源:互联网 发布:java项目介绍 编辑:程序博客网 时间:2024/05/16 19:28
一、基本知识
好多老师说,指针是C语言的重点中的重点,如果说C语言其它都学的很好,就是指针不会,那么C语言等于白学。接下来具体看一下指针的知识点吧。
1、指针变量只能存储地址
指针就一个作用:能够根据一个地址值,访问对应的存储空间。
例:
int *p;
int a = 90;
p = &a; //指针变量p指向变量a
*p = 10; //则a的值为10
2、常见指针形式
int* ip; //一个指向Int类型的指针
int** ip; //指向指针的指针
int *p[4]; //指针数组
int (*p)[4]; //指向数组的指针变量
int (*p)(); //指向函数的指针,函数没有参数,返回int类型
int (*p[])(); //指向函数的指针数组,函数没有参数,返回int类型
int (*(*f)(int,int))(int) //f是一个函数的指针,指向的函数的类型是有两个int参数并且返回一个函数指针的函数,返回的函数数指针指向有一个int参数并返回int的参数
分析:当看到这样的一个复杂的定义时,最好的处理方法就是从中间开始和向外扩张。“从中间开始”的意思是从变量名开始,这里指的是f。“向外扩展”的意思是先注意右边最近的项(在这个例子中f右边是右括号结束),然后注意左边(左边是*,表示是一个指针,指针指向一个...),然后注意左边(右边为(int,int),...带两个int类型参数的函数....),然后看左边(左边是*,表示函数返回的是一个指针),再看右边(右边是(int),...带一个int参数的函数...),再看左边(int指示函数返回int类型)。大多数申明都是以右-左-右....动作的方式工作的。
3、指针和引用的差别
(1)非空区别。在任何情况下都不能使用指向空值的引用。一个引用必须总是指向某个对象。因此如果你使用一个变量并且让它指向一个对象,但是该变量在某些时候也可能不指向任何对象,这个时候你应该把变量申明为指针,因为这样你可以赋空值给该变量。相反,如果变量肯定指向一个对象,例如你的设计不允许变量为空,这时你就可以把变量声明为引用。不存在指向空值的引用这个事实意味着使用引用的代码效率比使用指针要高。
(2)合法性区别。在使用引用之前不需要测试它的合法性。相反,指针则应该总是被测试,防止其为空。
(3)可修改性区别。指针与引用的另一个重要的区别是指针可以被重新赋值以能指向另一个不同的对象。但是引用则总是指向在初始化时被指定的对象,以后不能改变,但是指定的对象其内容可以改变。
4、变量赋值和取地址
赋值给变量
再看下面赋值:
i = 30;a = 't';
两个语句是将30存入i变量的内存空间中,将“t”字符存入a变量的内存空间中。我们可以利用这样的形象来理解:
变量在哪里?
即我想知道变量的地址。
好了,接下来我们来看看&i是什么意思?
是取i变量所在的地址编号嘛。我们可以这样读它:返回i变量的地址编号。
我要在屏幕上显示变量的地址值的话,可以写如下代码:
printf("%x", &i);
以上图的内存映象为例,屏幕上显示的不是i值30,而是显示i的内存地址编号6了。当然,在你的实际操作中,i变量的地址值不会是这个数了。
这就是我所认为的作为初学者应该能够想象到的变量存储的实质了。请这样理解吧。
最后总结代码如下:
#include "stdio.h"main(){ int i = 5; printf("%d\n", i); /*①*/ printf("%d\n", &i); /*②*/ return(0);}
现在你可知道①、②两个printf分别在屏幕上输出的是i的什么东西啊?
程序运行结果:
52686748Process returned 0 (0x0) execution time : 0.079 sPress any key to continue.
5、指针使用注意
1)不建议的写法, int *p只能指向int类型的数据
int *p;
double d = 10.0;
p = &d;
2)指针变量只能存储地址
int *p;
p = 200;
3)指针变量未经过初始化,不要拿来间接访问其他存储空间
int *p;
printf("%d\n", *p);
4)定义变量时的*仅仅是一个象征,没有其他特殊含义
int *p = &a;
5)不正确的写法
// *p = &a;
p = &a;
6) 这个时候的*的作用:访问指向变量p指向的存储空间
*p = 20;
6、指针例子
<p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(120, 73, 42);">#include <span style="color: #d12f1b"><stdio.h></span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"><span style="color: #bb2ca2">void</span> swap(<span style="color: #bb2ca2">int</span> *v1, <span style="color: #bb2ca2">int</span> *v2);</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"><span style="color: #bb2ca2">int</span> main()</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;">{</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #008400">/*</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"> int a = 10;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"> int b = 11;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0); min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"> swap(&a, &b);</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"> */</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #bb2ca2">int</span> a2 = <span style="color: #272ad8">90</span>;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #bb2ca2">int</span> b2 = <span style="color: #272ad8">89</span>;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> swap(&a2, &b2);</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> printf(<span style="color: #d12f1b">"a2=%d, b2=%d\n"</span>, a2, b2);</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #bb2ca2">return</span> <span style="color: #272ad8">0</span>;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;">}</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: 'Heiti SC Light'; color: rgb(0, 132, 0);"><span style="font-family: Menlo;">/* </span>不能交换外面实参的值,仅仅是交换了内部指针的指向</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);">void swap(int *v1, int *v2)</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);">{</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"> int *temp;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"> temp = v1;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"> v1 = v2;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"> v2 = temp;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);">}*/</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: 'Heiti SC Light'; color: rgb(0, 132, 0);"><span style="font-family: Menlo;">// </span>完成两个整型变量值的互换</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"><span style="color: #bb2ca2">void</span> swap(<span style="color: #bb2ca2">int</span> *v1, <span style="color: #bb2ca2">int</span> *v2)</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;">{</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #bb2ca2">int</span> temp = *v1;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> *v1 = *v2;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> *v2 = temp;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;">}</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: 'Heiti SC Light'; color: rgb(0, 132, 0);"><span style="font-family: Menlo;">/* </span>交换的只是内部<span style="font-family: Menlo;">v1</span>、<span style="font-family: Menlo;">v2</span>的值</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);">void swap(int v1, int v2)</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);">{</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"> int temp = v1;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"> v1 = v2;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"> v2 = temp;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);">}*/</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"></p>
二、指针和数组
1、通过数组名访问数组元素
看下面代码:
int i, a[] = {3,4,5,6,7,3,7,4,4,6};for (i = 0; i <= 9; i++){printf("%d\n", a[i]);}
很显然,它是显示a 数组的各元素值。
我们还可以这样访问元素,如下:
int i, a[] = {3,4,5,6,7,3,7,4,4,6};for (i = 0; i <= 9; i++){printf("%d\n", *(a+i));}
它的结果和作用完全一样。
2、通过指针访问数组元素
int i, *pa, a[] = {3,4,5,6,7,3,7,4,4,6};pa = a; /*请注意数组名a直接赋值给指针pa*/for (i = 0; i <= 9; i++){printf("%d\n", pa[i]);}
很显然,它也是显示a 数组的各元素值。
另外与数组名一样也可如下:
int i, *pa, a[] = {3,4,5,6,7,3,7,4,4,6};pa = a;for (i = 0; i <= 9; i++){printf("%d\n", *(pa+i));}看pa = a,即数组名赋值给指针,以及通过数组名、指针对元素的访问形式看,它们并没有什么区别,从这里可以看出:数组名其实也就是指针。
3、数组名与指针变量的区别
int i, *pa, a[] = {3,4,5,6,7,3,7,4,4,6};pa = a;for (i = 0; i <= 9; i++){printf("%d\n", *pa);pa++; /*注意这里,指针值被修改*/}
可以看出,这段代码也是将数组各元素值输出。不过,你把循环体{}中的pa改成a试试。你会发现程序编译出错,不能成功。看来指针和数组名还是不同的。其实上面的指针是指针变量,而数组名只是一个指针常量。这个代码与上面的代码不同的是,指针pa在整个循环中,其值是不断递增的,即指针值被修改了。数组名是指针常量,其值是不能修改的,因此不能类似这样操作:a++。
前面pa[i],*(pa+i)处,指针pa的值是使终没有改变。所以变量指针pa与数组名a可以互换。
4、指针变量的+1究竟加多少,取决于指针的类型
int * 4
char * 1
double * 8
5、例子:
<p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(120, 73, 42);">#include <span style="color: rgb(209, 47, 27);"><stdio.h></span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"><span style="color: rgb(187, 44, 162);">void</span> change(<span style="color: rgb(187, 44, 162);">int</span> array[]);</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"><span style="color: #bb2ca2">int</span> main()</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;">{</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"><span style="color: #000000"> </span>// 20<span style="font-family: 'Heiti SC Light';">个字节</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #bb2ca2">int</span> ages[<span style="color: #272ad8">5</span>] = {<span style="color: #272ad8">10</span>, <span style="color: #272ad8">11</span>, <span style="color: #272ad8">19</span>, <span style="color: #272ad8">78</span>, <span style="color: #272ad8">67</span>};</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> change(ages);</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #bb2ca2">return</span> <span style="color: #272ad8">0</span>;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;">}</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: 'Heiti SC Light'; color: rgb(0, 132, 0);"><span style="font-family: Menlo;">// </span>利用一个指针来接收一个数组,指针变量<span style="font-family: Menlo;">array</span>指向了数组的首元素</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"><span style="color: #bb2ca2">void</span> change(<span style="color: #bb2ca2">int</span> *array)</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;">{</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> printf(<span style="color: #d12f1b">"%d\n"</span>, array[<span style="color: #272ad8">2</span>]);</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"><span style="color: #000000"> </span>//printf("%d\n", *(array+2));</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;">}</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);">/*</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);">void change(int array[])</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);">{</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"> int s = sizeof(array);</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0); min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"> printf("%d\n", s);</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);">}*/</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"><span style="color: #bb2ca2">void</span> test()</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;">{</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #bb2ca2">double</span> d = <span style="color: #272ad8">10.8</span>;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #bb2ca2">double</span> *dp;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> dp = &d;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> printf(<span style="color: #d12f1b">"dp = %p\n"</span>, dp);</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> printf(<span style="color: #d12f1b">"dp + 1 = %p\n"</span>, dp + <span style="color: #272ad8">1</span>);</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #bb2ca2">int</span> ages[<span style="color: #272ad8">5</span>] = {<span style="color: #272ad8">10</span>, <span style="color: #272ad8">9</span>, <span style="color: #272ad8">8</span>, <span style="color: #272ad8">67</span>, <span style="color: #272ad8">56</span>};</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #bb2ca2">int</span> *p;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: 'Heiti SC Light'; color: rgb(0, 132, 0);"><span style="font-family: Menlo; color: rgb(0, 0, 0);"> </span><span style="font-family: Menlo;">// </span>指针变量<span style="font-family: Menlo;">p</span>指向了数组的首元素</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> p = &ages[<span style="color: #272ad8">0</span>];</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: 'Heiti SC Light'; color: rgb(0, 132, 0);"><span style="font-family: Menlo; color: rgb(0, 0, 0);"> </span><span style="font-family: Menlo;">// </span>数组名就是数组的地址,也是数组首元素的地址</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"><span style="color: #000000"> </span>//p = ages;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #008400">/*</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"> p ---> &ages[0]</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"> p + 1 ---> &ages[1]</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"> p + 2 ---> &ages[2]</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"> p + i ---> &ages[i]</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"> */</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"><span style="color: #000000"> </span>//printf("%d\n", *(p+2));</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> printf(<span style="color: #d12f1b">"%d\n"</span>, p[<span style="color: #272ad8">2</span>]);</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #008400">/*</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"> for (int i = 0; i<5; i++) {</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"> printf("ages[%d] = %d\n", i, *(p+i));</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"> }*/</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"><span style="color: #000000"> </span>// printf("%p\n", p);</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"><span style="color: #000000"> </span>// printf("%p\n", p + 1);</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"><span style="color: #000000"> </span>// printf("%p\n", p + 2);</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;">}</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"></p>
三、指针和字符串
1、内存
1.常量区,存放一些常量字符串。如:13432abcdefg
2.堆,存放对象。
3.栈,存放局部变量。 如字符串、数组、变量等。
例子:
int main()
{
char name[] = "it";
//"it" == 'i' + 't' + '/0'
//指针变量name2指向了字符串的首字符
char *name2 = "it";
//printf("%c\n", *name2); 输出为“i”
//printf("%s\n",name2); 输出为“it”
//字符串变量
char name[] = "it";
name[0] = 'T';
// "it" == 't' + 't' + '/0'
//字符串常量。指针变量name2指向字符串的首字符。
char *name2 = "it";
char *name3 = "it";
printf(“%p\n%p\n”,name2,name3) //输出结果可以看到,name2 和name3 指向同一地址
}
2、定义字符串的两种方式
1.利用数组
char name[] = "itcast";
特点:字符串里面的字符是可以修改的
使用场合:字符串的内容需要经常修改
2.利用指针
char *name = "itcast";
特点:字符串其实是一个常量字符串,里面的字符不可以修改
使用场合:字符串的内容不需要修改,而且这个字符串经常使用
3.定义字符串数组的两种方式
1.指针数组(字符串数组)
char *names[5] = {"jack","rose","jack"};
2.二维字符数组(字符串数组)
char names2[2][10] = {"jack","rose"};
4.字符串输入
char name[20];
printf("请输入姓名:\n");
scanf ("%s",name);
//如果输入jack
printf("%s\n",name); //输出jack
printf("%c\n",name[3]"); //输出k
四、其它
1、返回指针的函数
int main()
{
char *name = test();
printf("name=%s\n",name);
return 0;
}
char *test()
{
return "rose";
}
2、指向函数的指针
1)
<span style="font-size:14px;">void test(){ printf("调用了test函数\n");}int main(){ //(*p)是固定写法,代表指针变量p将来肯定是指向函数 //左边的void:指针变量p指向的函数没有返回值 //右边的():指针变量p指向的函数没有形参 void (*p)(); //指针变量p指向了test函数 p = test; p(); //第一种。 //(*p)(); //第二种。利用指针变量间接调用函数 //test(); //第三种。直接调用函数}</span>2)
<p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(209, 47, 27);"><span style="color: #78492a">#include</span><stdio.h></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"><span style="color: #bb2ca2">void</span> main()</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;">{</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="font-family: 'Heiti SC Light';"> </span><span style="color: #bb2ca2">int</span> max(<span style="color: #bb2ca2">int</span>,<span style="color: #bb2ca2">int</span>);</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="font-family: 'Heiti SC Light';"> </span><span style="color: #bb2ca2">int</span>(*p)(<span style="color: #bb2ca2">int</span>,<span style="color: #bb2ca2">int</span>);</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="font-family: 'Heiti SC Light';"> </span><span style="color: #bb2ca2">int</span> a,b,c;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="font-family: 'Heiti SC Light';"> </span>p = <span style="color: #31595d">max</span>;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="font-family: 'Heiti SC Light';"> </span><span style="color: #3d1d81">scanf</span>(<span style="color: #d12f1b">"%d,%d"</span>,&a,&b);</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="font-family: 'Heiti SC Light';"> </span>c = (*p)(a,b);</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(209, 47, 27);"><span style="color: #000000"> </span><span style="font-family: 'Heiti SC Light'; color: rgb(0, 0, 0);"> </span><span style="color: #3d1d81">printf</span><span style="color: #000000">(</span>"a = %d,b = %d,max = %d\n"<span style="color: #000000">,a,b,c);</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;">}</p>
(1),“int(*p)(int,int);”用来定义p是一个指向函数的指针变量,*p两端的括号绝对不能省略。
(2),"p = max"的作用是将函数max的入口地址赋给指针变量p。和数组名代表数组首元素地址类似,函数名代表该函数的入口地址。(同理:max++是错误的)
(3),指向函数的指针变量的一般定义形式:
数据类型(*指针变量名)(函数参数表列);
3、指向指针的指针
(1)定义
char **p;
谨记:*p是**p的地址,p是**p的地址,**p是变量。p和*p都是地址;
p前面有两个*号,*运算符的结合性是从右到左,因此**p相当于*(*p),显然*p是指针变量的定义形式。
五、应用
1、练习题1
<p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(120, 73, 42);">#include <span style="color: #d12f1b"><stdio.h></span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"><span style="color: #bb2ca2">int</span> main()</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;">{</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #bb2ca2">double</span> d = <span style="color: #272ad8">10.5</span>;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #bb2ca2">double</span> d2 = <span style="color: #272ad8">10.5</span>;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #bb2ca2">double</span> *p;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> p = &d;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> *p = <span style="color: #272ad8">10.9</span>;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> p = &d2;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> *p = <span style="color: #272ad8">10.9</span>;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> printf(<span style="color: #d12f1b">"d=%f, d2=%f\n"</span>, d, d2);</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"><span style="color: #000000"> </span>// <span style="font-family: 'Heiti SC Light';">清空指针</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> p = <span style="color: #272ad8">0</span>;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"><span style="color: #000000"> </span>// p = NULL;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: 'Heiti SC Light'; color: rgb(0, 132, 0);"><span style="font-family: Menlo; color: rgb(0, 0, 0);"> </span><span style="font-family: Menlo;">// </span>清空指针后,不能再间接访问其他存储空间</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"><span style="color: #000000"> </span>// *p = 100.7;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #bb2ca2">return</span> <span style="color: #272ad8">0</span>;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;">}</p>2、指针和字符串练习题
<p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(120, 73, 42);">#include <span style="color: #d12f1b"><stdio.h></span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);">/*</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"> (<span style="font-family: 'Heiti SC Light';">不包括</span>\0)</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"> <span style="font-family: 'Heiti SC Light';">编写一个</span>int string_len(char *s)<span style="font-family: 'Heiti SC Light';">,返回字符串</span>s<span style="font-family: 'Heiti SC Light';">的字符长度</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0); min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"> */</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"><span style="color: #bb2ca2">int</span> string_len(<span style="color: #bb2ca2">char</span> *s);</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"><span style="color: #bb2ca2">int</span> main()</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;">{</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"><span style="color: #000000"> </span>//char *name = "itcast";</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"><span style="color: #000000"> </span>// <span style="font-family: 'Heiti SC Light';">男</span> \u434\u4343\u434</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #bb2ca2">int</span> size = <span style="color: #31595d">string_len</span>(<span style="color: #d12f1b">"tre777"</span>);</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #3d1d81">printf</span>(<span style="color: #d12f1b">"%d\n"</span>, size);</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #bb2ca2">return</span> <span style="color: #272ad8">0</span>;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;">}</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"><span style="color: #bb2ca2">int</span> string_len(<span style="color: #bb2ca2">char</span> *s)</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;">{</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: 'Heiti SC Light'; color: rgb(0, 132, 0);"><span style="font-family: Menlo; color: rgb(0, 0, 0);"> </span><span style="font-family: Menlo;">// 1.</span>定义一个新的指针变量指向首字符</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #bb2ca2">char</span> *p = s;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #008400">/*</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"> while ( *s != '\0' )</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"> {</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"> s++;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"> }*/</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #bb2ca2">while</span> ( *s++ ) ;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #bb2ca2">return</span> s - p - <span style="color: #272ad8">1</span>;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;">}</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"><span style="color: #bb2ca2">void</span> test1()</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;">{</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #bb2ca2">int</span> string_len(<span style="color: #bb2ca2">char</span> *s)</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> {</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"><span style="color: #000000"> </span>// <span style="font-family: 'Heiti SC Light';">记录字符的个数</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #bb2ca2">int</span> count = <span style="color: #272ad8">0</span>;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: 'Heiti SC Light'; color: rgb(0, 132, 0);"><span style="font-family: Menlo; color: rgb(0, 0, 0);"> </span><span style="font-family: Menlo;">// </span>如果指针当前指向的字符不是<span style="font-family: Menlo;">'\0'</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"><span style="color: #000000"> </span>// <span style="font-family: 'Heiti SC Light';">首先</span>*s<span style="font-family: 'Heiti SC Light';">取出指向的字符</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"><span style="color: #000000"> </span>// <span style="font-family: 'Heiti SC Light';">然后</span>s++</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #bb2ca2">while</span> ( *s++ )</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> {</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"><span style="color: #000000"> </span>// <span style="font-family: 'Heiti SC Light';">个数</span>+1</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> count++;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: 'Heiti SC Light'; color: rgb(0, 132, 0);"><span style="font-family: Menlo; color: rgb(0, 0, 0);"> </span><span style="font-family: Menlo;">// </span>让指针指向下一个字符</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"><span style="color: #000000"> </span>//s = s + 1;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"><span style="color: #000000"> </span>//s++;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> }</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #bb2ca2">return</span> count;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> }</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;">}</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"><span style="color: #bb2ca2">void</span> test2()</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;">{</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #bb2ca2">int</span> string_len(<span style="color: #bb2ca2">char</span> *s)</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> {</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"><span style="color: #000000"> </span>// <span style="font-family: 'Heiti SC Light';">记录字符的个数</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #bb2ca2">int</span> count = <span style="color: #272ad8">0</span>;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: 'Heiti SC Light'; color: rgb(0, 132, 0);"><span style="font-family: Menlo; color: rgb(0, 0, 0);"> </span><span style="font-family: Menlo;">// </span>如果指针当前指向的字符不是<span style="font-family: Menlo;">'\0'</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #bb2ca2">while</span> ( *s != <span style="color: #272ad8">'\0'</span>)</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> {</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"><span style="color: #000000"> </span>// <span style="font-family: 'Heiti SC Light';">个数</span>+1</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> count++;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: 'Heiti SC Light'; color: rgb(0, 132, 0);"><span style="font-family: Menlo; color: rgb(0, 0, 0);"> </span><span style="font-family: Menlo;">// </span>让指针指向下一个字符</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; color: rgb(0, 132, 0);"><span style="color: #000000"> </span>//s = s + 1;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> s++;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> }</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo; min-height: 13px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> <span style="color: #bb2ca2">return</span> count;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"> }</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 11px; font-family: Menlo;"></p>
- 黑马程序员:c语言--指针
- 黑马程序员-C语言指针
- 黑马程序员---C语言指针
- 黑马程序员---C语言指针
- 黑马程序员--C语言-指针
- 黑马程序员------C语言-----指针
- 黑马程序员---c语言--指针
- 黑马程序员---c语言 指针
- 【黑马程序员】【C语言】指针
- 黑马程序员--C语言指针
- 黑马程序员-C语言-指针
- 黑马程序员-C语言-指针
- 黑马程序员—C语言_指针
- 黑马程序员 C语言-----指针学习
- 黑马程序员——C语言指针
- 黑马程序员-c语言指针的学习。
- 黑马程序员 C语言 - 07 指针
- 黑马程序员—C语言—指针
- X5开发工具 使用execl导入组件 导入数据后 对导入数据进行处理
- Python学习资料
- SharePoint 2013 日历重叠功能简介
- Spring 中的p标签
- 防火墙配置基础
- 黑马程序员--C语言-指针
- SQL AVG 函数
- 破茧成蝶,必将云开月明
- 十大数据挖掘算法及各自优势
- struts2的拦截器
- 【LeetCode】Trapping Rain Water
- HttpServletRequest中getAttribute()和getParameter()的区别
- linux 网络基本知识
- div弹出窗口在frameset外层解决方案