指针数组与指向指针的指针

指针数组与指向指针的指针

http://wlkc.gdqy.edu.cn/jpkc/portal/blob?key=173314

 

 

指针数组和数组指针的区别

http://allew.blog.163.com/blog/static/3374389720094148449239/

 

 

指针数组[组图]

http://school.cnd8.com/c/jiaocheng/9212.htm

 

函数指针和指针函数

http://lionwq.spaces.eepw.com.cn/articles/article/item/18258

 

========================================

 

source 1

#include <stdio.h> int main(void) { char *ptr[4] = {"beijing", "shanghai", "tianjin", "chongqing"}; int i, *iptr[3], a[3]={1,2,3},b[3][2]={1,2,3,4,5,6}; for(i=0; i<4; i++) printf("%s/t", ptr[i]); printf("/n"); for(i=0; i<3; i++) iptr[i]=&a[i]; for(i=0; i<3; i++) printf("%d/t", *iptr[i]); printf("/n"); for(i=0; i<3; i++) iptr[i]=b[i]; for(i=0; i<3; i++) printf("%d:%d/t", *iptr[i], *iptr[i]+1); printf("/n"); return 0; }  

 

result 1:

 

[[email protected] c++]$ gcc -o array_ptr array_ptr.c 

[[email protected] c++]$ ./array_ptr 

beijing shanghai        tianjin chongqing

1       2       3

1:2     3:4     5:6

 

 

 

========================

 

source 2

#include <stdio.h> #include <string.h> #include <stdlib.h> void show(char *ptr[], int); void sort(char *ptr[], int); int main(void) { char *ptr[4], *tmp; int i; for(i=0; i<4; i++) { ptr[i] = (char *)malloc(20); fgets(ptr[i], 20, stdin); } show(ptr, 4); sort(ptr, 4); show(ptr, 4); return 0; } void show(char *ptr[], int num) { int i; for(i=0; i<num; i++) printf("%10s", ptr[i]); printf("/n"); //换行 } void sort(char *ptr[], int num) { int i, j; char *tmp; for(i=0; i<num-1; i++) for(j=0; j<num-1-i; j++) { if(strcmp(ptr[j], ptr[j+1])>0) { tmp = ptr[j]; ptr[j]=ptr[j+1]; ptr[j+1]=tmp; } } }  

 

result 2:

 

[[email protected] c++]$ ./array_ptr_sort 

beijing

shanghai

tianjin

chongqing

 

  beijing

 shanghai

  tianjin

chongqing

 

  beijing

chongqing

 shanghai

  tianjin

 

=================================

 

指针函数

 

Source

#include <stdio.h> int main() { char *ch(char *, char *); char str1[] = "I am glad to meet you"; char str2[] = "Welcome to study C"; printf("%s/n", ch(str1, str2)); return 0; } char *ch(char *str1, char *str2) { int i; char *p = str2; //指针赋值 printf("str1: %s/nstr2: %s/n", str1, str2); return p; //返回指针 }  

 

Result

 

[[email protected] c++]$ gcc -o func_pfun func_pfun.c 

[[email protected] c++]$ ./func_pfun                  

str1: I am glad to meet you

str2: Welcome to study C

Welcome to study C

 

 

 

 

=================================

 

函数指针

 

 

Source

#include <stdio.h> int main() { int max(int, int); int i, a, b, m; int (*f)(); //定义函数指针 scanf("%d %d", &a, &b); f = max; //给函数指针f赋值，使它指向函数max m = (*f)(a, b); //通过函数指针f调用函数max printf("%d %d max: %d/n", a, b, m); return 0; } int max(int x, int y) { return x>y ? x:y; }  

 

Result

 

[email protected] c++]$ gcc -o func_ptr func_ptr.c   

[[email protected] c++]$ ./func_ptr 

3 6

3 6 max: 6