指针数组做函数参数的退化

来源：互联网发布：p2p下载软件哪个好编辑：程序博客网时间：2024/05/21 16:20
#include "stdio.h"#include "string.h"#include "stdlib.h"#include <stdio.h>#include <string.h>//演示：指针数组的用法//演示：找错误 注意return//求关键字在表中的位置//一个入口 多个出口int searcheKeyTable(const char* table[], const int size, const char* key, int *pos){int rv = 0;int i = 0;int inum = 0;if (table==NULL || key==NULL || pos==NULL){rv = -1;printf("func searcheKeyTable:%d", rv);return rv;}//间接的证明  数组做函数参数的退回  inum = (sizeof(table)/sizeof(*table));//inum = 1for(i=0; i<size; i++){if( strcmp(key, table[i]) == 0 ){*pos = i;//break;return rv;}}//没有找到返回-1if (i == size){*pos = -1;}return rv;}#define DIM(a) (sizeof(a)/sizeof(*a))int main411(){int inum = 0;int pos = 0;int a[10];int i = 0;//指针数组char*   c_keyword[] = {"while", "case","static","do"};searcheKeyTable( c_keyword, DIM(c_keyword),"do", &pos);// ===> 带参数的宏//searcheKeyTable( c_keyword, (sizeof(c_keyword)/sizeof(*c_keyword)),"do", &pos);//searcheKeyTable( c_keyword, inum,"do", &pos);printf("pos:%d\n", pos);//searcheKeyTable(NULL, DIM(c_keyword),"do", &pos);//printf("pos:%d\n", pos);searcheKeyTable( c_keyword, DIM(c_keyword), "static", &pos);printf("pos:%d\n", pos);system("pause");return ;}//main函数是操作系统调用的函数//在程序执行的时候可以向main函数传递参数/*argc 命令行参数argv 命令行参数数组env  函数变量数组int main();int main(int argc);int main(int argc, char *argv[])*/int main477(int argc, char* argv[], char**env){int i = 0;//main02_1();printf("******************* Begin argv *******************\n");for(i=0; i<argc; i++){printf("%s\n", argv[i]);}// for(i=0; argv[i]!=NULL; i++)// {// printf("%s\n", argv[i]);// }printf("******************* End argv *******************\n");printf("\n");printf("\n");printf("\n");printf("******************* Begin env *******************\n");for(i=0; env[i]!=NULL; i++)  //{printf("%s\n", env[i]);}printf("******************* End env*******************\n");getchar();}void main(){int inum = 0;int pos = 0;int a[10];int i = 0;//指针数组  自我结束能力char*   c_keyword[] = {"while", "case","static","do",'\0'};  char*   c_keyword2[] = {"while", "case","static","do",0}; char*   c_keyword3[] = {"while", "case","static","do",NULL}; for (i=0; c_keyword[i] != NULL; i++){printf("%s\n", c_keyword[i]);}printf("\n....\n");for (i=0; c_keyword2[i] != NULL; i++){printf("%s\n", c_keyword2[i]);}printf("\n....\n");for (i=0; c_keyword3[i] != NULL; i++){printf("%s\n", c_keyword3[i]);}system("pause");}int main45(){int inum = 0;int pos = 0;int a[10];int i = 0;//指针数组char*   c_keyword[] = {"while", "case","static","do",'\0'};// NULL   0  '\0'for(i=0; c_keyword[i]!=NULL; i++){printf("%s\n", c_keyword[i]);}system("pause");}
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