指针数组的应用场景之main函数

#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));

for(i=0; i<size; i++)
{
if( strcmp(key, table[i]) == 0 )
{
*pos = i;
//break;
return rv;
}
}

//没有找到返回-1
if (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");
}