二级指针:指向指针的指针
指针数组:元素是指针的数组
int lookup_keyword(char *desire_word,char **keytable,int size) //char *keytable[],因为keytable[]可写成指针形式 故= char **keytable { char **kwp = NULL; for(kwp=keytable;kwp<keytable+size;kwp++) { if(strcmp(desire_word,*kwp)==0) { return kwp-keytable; } } return -1; } int main() { char **key = NULL; char *keyword[] = { //该例中 keyword必须定义为指针数组,每个元素指向字符串常量 "hello", "nice", "eat" }; key = keyword; //二级指针 = 字符指针数组首元素地址(类型为char * *类型一致) int i = lookup_keyword("eat",keyword,3); printf("i=%d\n",i); return 0; }
类似有 int main(int argc,char *argv[]) = int main(int argc,char **argv) ,argc参数个数,argv指针数组
./main a b c d 有 argc = 5, 打印各值 argv[0] ->main,argv[1] ->a,argv[2]->b,argv[3]->c,argv[4]->d