我没有到这里来的?
这非常有效:
for ( i = 0; i < 5 && found != 0 ;++i ){ no difference than above
found=strcmp( name, myContacts[i].cFirstName);
printf(" i %d\n", i);
}
printf(" \nName Found %s", myContacts[i-1].cFirstName );
但出于好奇,我正在尝试使用strstr()。
/*** This achieves the same functionality as above ***/
for ( i = 0; i < 5 ;i++ ){
found2=strstr( myContacts[i].cFirstName , name);
printf(" i %d\n", i);
if (found2 != NULL)
{
printf(" \nName Found %s", myContacts[i].cFirstName );
break;
}
}
然而这不起作用:
for ( i = 0; i < 5 && found2 != '\0' ;i++ ){ //this does not work as above
for ( i = 0; i < 5 && found2 != NULL ;i++ ){ // this also is not wroking
found2=strstr( myContacts[i].cFirstName , name);
}
printf(" \nName Found %s", myContacts[i].cFirstName );
提前感谢您的建议。
完整代码:
# please take my codes with a grain of skepticism, I am still learning
# i know of sizeof(), but I rather not use it just for the purpose of my exercise
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#define MAXBUFFERSIZE 10
typedef struct contact {
char cFirstName[10];
char cLastName[10];
char cTelphone[12];
} address ; // end type
// function prototype
void printContacts( address * );
void printMenu();
char getChoice();
void storeContact( address [] , int *);
//int searchContact( address [] , char * );
void searchContact( address [] , char [] );
int main(){
char cSelection = 0;
address myContacts[5];
char buffer[MAXBUFFERSIZE];
int i ;
// initialize array to be zeros
for ( i = 0; i < 5 ; i++ ){
strcpy(myContacts[i].cFirstName, "0");
strcpy(myContacts[i].cLastName,"0");
strcpy(myContacts[i].cTelphone,"0");
}
strcpy(myContacts[0].cFirstName, "Jonny");
strcpy(myContacts[1].cFirstName, "Julia");
strcpy(myContacts[2].cFirstName, "Claudia");
strcpy(myContacts[3].cFirstName, "Aaron");
strcpy(myContacts[4].cFirstName, "Sebastian");
int iDel = -1 ; // store the position if one deleted
int iCount = 0 ; // counter for position in the array, when
// inserting names.
while ( cSelection != '5' ) {
printMenu();
cSelection = getChoice();
switch (cSelection) {
case '1':
printContacts( myContacts );
break;
case '2':
if ( ( iDel >= -1 ) && ( iCount < 5 ) ){
//printf("\niCount is %d ", iCount);
storeContact( myContacts, &iCount );
iCount++;
//printf("\nOutside storeContact, *Plocation %d", iCount );
}
if ( iCount >= 5 ) {
printf("\nThe Memory is full, consider deleting some"\
"Contacts");
}
break;
case '3':
{
printf("\nEnter a name or part of a name to search:\n");
fscanf(stdin, "%s", buffer);
getchar(); // clear the last enter
printf("\nThe line you entered was:\n");
printf("%s\n", buffer);
searchContact( myContacts, buffer );
break;
}
case '4':
//iDel=deleteContact( myContacts );
break;
}// end of switch
}// end of while
return 0;
} // end main
char getChoice(){
char cSelection = 'q'; //for the menu
/**** always scanf CHARS so you can check
* if digit or char !!! ****/
scanf("%s", &cSelection);
while ( strlen(&cSelection) != 1 ){
printf("\nChoich not understood, enter a number again:");
scanf("%s",&cSelection);
}
if ( isalpha(cSelection) ){
printf( "You entered a letter of the alphabet\n" );
cSelection = -1;
printf( "Illegal choice !!!" );
}
return cSelection;
}
void printContacts( address * myContacts ){
int i ;
for ( i = 0; strcmp(myContacts[i].cFirstName,"0") != 0 && i < 5 ; i++ ){
printf("\nmyContacts[%d].cFirstName: %s", i, \
myContacts[i].cFirstName );
}// end for
}
void printMenu(){
printf("\n\n\tSilly Phone Book\n\n");
printf("\n\n1\tPrint Phone Book\n");
printf("2\tAdd New Contact\n");
printf("3\tSearch For Contact\n");
printf("4\tDelete Contact\n");
printf("5\tQuit\n");
printf("\nSelect Action: ");
}
//void storeContact( address myContacts[] ){ //syntactic sugar
void storeContact( address * myContacts, int *Plocation ){
char ch; /* handles user input */
char buffer[MAXBUFFERSIZE]; /* sufficient to handle one line */
int x = 0;
x=*Plocation;
ch = getchar(); // clear the last enter
printf("Enter a name (<10 characters)\n");
//ch = getchar();
//char_count = 0;
//while( (ch != '\n') && (ch != EOF ) && (char_count < MAXBUFFERSIZE)) {
//buffer[char_count++] = ch;
//ch = getchar();
//}
//buffer[char_count] = 0x00; /* null terminate buffer */
//fgets(buffer,11,stdin);
fscanf(stdin, "%s", buffer); /* read from keyboard */
printf("\nThe line you entered was:\n");
printf("%s\n", buffer);
//TODO: add check that string is not too long!!!
// if we do that, the code won't blow here ?
strcpy(myContacts[x].cFirstName, buffer);
}
//int searchContact( address * myContacts, char name[] ){
void searchContact( address * myContacts, char * name ){
int found;
char *found2;
//printf("\nHey dude im buffer from inside searchContact: %s", name);
// iterate throught the array, print possible matches
int i = 0;
//for ( i = 0; i < 5 && found != 0 ;i++ ){
//for ( i = 0; i < 5 && found != 0 ;++i ){ no difference than above
//found=strcmp( name, myContacts[i].cFirstName);
//printf(" i %d\n", i);
//}
//printf(" \nName Found %s", myContacts[i-1].cFirstName );
/*** This achieves the same functionality as above
for ( i = 0; i < 5 ;i++ ){
found2=strstr( myContacts[i].cFirstName , name);
printf(" i %d\n", i);
if (found2 != NULL)
{
printf(" \nName Found %s", myContacts[i].cFirstName );
break;
}
} ***/
for ( i = 0; i < 5 && &found2 != '\0' ;i++ ){ //this does not work as above
found2=strstr( myContacts[i].cFirstName , name);
printf("found %p i %d\n", found2, i);
//printf(" \nName Found %s", myContacts[i].cFirstName );
}
//return found;
} // end of searchContacts if ( isalpha(cSelection) ){
printf( "You entered a letter of the alphabet\n" );
cSelection = -1;
printf( "Illegal choice !!!" );
}
return cSelection;
}
void printContacts( address * myContacts ){
int i ;
for ( i = 0; strcmp(myContacts[i].cFirstName,"0") != 0 && i < 5 ; i++ ){
printf("\nmyContacts[%d].cFirstName: %s", i, \
myContacts[i].cFirstName );
}// end for
}
void printMenu(){
printf("\n\n\tSilly Phone Book\n\n");
printf("\n\n1\tPrint Phone Book\n");
printf("2\tAdd New Contact\n");
printf("3\tSearch For Contact\n");
printf("4\tDelete Contact\n");
printf("5\tQuit\n");
printf("\nSelect Action: ");
}
//void storeContact( address myContacts[] ){ //syntactic sugar
void storeContact( address * myContacts, int *Plocation ){
char ch; /* handles user input */
char buffer[MAXBUFFERSIZE]; /* sufficient to handle one line */
int x = 0;
x=*Plocation;
ch = getchar(); // clear the last enter
printf("Enter a name (<10 characters)\n");
//ch = getchar();
//char_count = 0;
//while( (ch != '\n') && (ch != EOF ) && (char_count < MAXBUFFERSIZE)) {
//buffer[char_count++] = ch;
//ch = getchar();
//}
//buffer[char_count] = 0x00; /* null terminate buffer */
//fgets(buffer,11,stdin);
fscanf(stdin, "%s", buffer); /* read from keyboard */
printf("\nThe line you entered was:\n");
printf("%s\n", buffer);
//TODO: add check that string is not too long!!!
// if we do that, the code won't blow here ?
strcpy(myContacts[x].cFirstName, buffer);
}
//int searchContact( address * myContacts, char name[] ){
void searchContact( address * myContacts, char * name ){
int found;
char *found2;
//printf("\nHey dude im buffer from inside searchContact: %s", name);
// iterate throught the array, print possible matches
int i = 0;
//for ( i = 0; i < 5 && found != 0 ;i++ ){
//for ( i = 0; i < 5 && found != 0 ;++i ){ no difference than above
//found=strcmp( name, myContacts[i].cFirstName);
//printf(" i %d\n", i);
//}
//printf(" \nName Found %s", myContacts[i-1].cFirstName );
/*** This achieves the same functionality as above
for ( i = 0; i < 5 ;i++ ){
found2=strstr( myContacts[i].cFirstName , name);
printf(" i %d\n", i);
if (found2 != NULL)
{
printf(" \nName Found %s", myContacts[i].cFirstName );
break;
}
} ***/
for ( i = 0; i < 5 && found2 != '\0' ;i++ ){ //this does not work as above
found2=strstr( myContacts[i].cFirstName , name);
printf("found %p i %d\n", found2, i);
//printf(" \nName Found %s", myContacts[i].cFirstName );
}
//return found;
} // end of searchContacts
为了完成这个讨论,我正在添加最终真正有效的内容。 这是在完成所有答案之后,所以感谢大家:
我忘了初始化指针:
char *found2=NULL;
现在,以下循环按预期工作:
for ( i = 0; i < 5 && !found2 ;i++ ){ //this does work as above
found2=strstr( myContacts[i].cFirstName , name);
printf("i %d\n", i);
}
printf("Name found %s", found2);
我希望这个功能与strstr()一起使用,因为现在我可以搜索“Clau”并将其与“Claudia”匹配。 这比strcmp()更适合我的需求,虽然我很确定它也可以用strcmp()来完成,C语言比我更复杂或更好。
再次感谢您的回答!
答案 0 :(得分:1)
您的found2
是char *
。
你应该写for (i = 0; i < 5 && !found2; i++) //etc etc
(或在循环中测试found2
并在非NULL时中断<)>
答案 1 :(得分:1)
不要使用cicles。 通过使用strstr(),你只需要使用它一次:
found2=strstr( myContacts[i].cFirstName , name);
printf(" \nName Found %s", found2 );
(不要忘记相应的空检查)
答案 2 :(得分:1)
条件为for
循环:
&found2 != '\0'
你想检查found2
是否指向NULL
,你甚至提到自己,所以请found2 != NULL
。否则,您将found2
的地址与NUL字符('\0'
)进行比较,这绝对不是您想要做的。
但是,如果strstr
代码段与strcmp
代码段具有相同的功能,那么您也错了。这两个功能完全不同。 Read the documentation for strstr
另一件事,在你的第一个片段"Name Found"
中总是会被打印
您的代码还有很多错误,例如:
scanf("%s", &cSelection);
...
while ( strlen(&cSelection)
cSelection
被声明为char
,如果您想在其中存储char
,请使用格式说明符%c
。如果您想要读取整个字符串,请将其设为char
数组,并且在将数组地址传递给函数时不需要&
。
&cSelection
传递给strlen
的同一个敌人。因为同样的原因没有任何意义。
(f)scanf
对于读取字符串也不安全,并且可能导致缓冲区溢出,您应该使用fgets(STRING, SIZE, stdin)
。无论如何只需打开你的编译器警告,这样你就可以捕获上述所有内容。