Classic phone book( and yes this is MY source code not ripped off)

[Tc Diehl]

Completely new to any sort of programming at all, the problem i am having right now, is trying to figure out how to not exit program after i add a new entry. I know probably simple fix. Any suggestions for the sorting part i will need later? Quick sort is worth bonus. Dont know how to use pointers at all.

#include<stdio.h>
#include<stdlib.h>
#include<string.h>

//strcmp
//strcpy

int i;

void Createnew(void);

void delete(void);

struct entry

     {
        char name[12];

        char surname[12];
        
        char number[12];
    

    };

struct entry f[20];



void Createnew(void)
{

       printf("Enter Name\n");

    i=0;

    scanf("%s", f[i].name);

    printf("Enter Surname\n");

    scanf("%s", f[i].surname);

    printf("Enter Phone Number\n");

    scanf("%s", f[i].number);


}

void delete()
    {




    printf("Enter index of entry to delete\n");

    scanf("%i",&i);

    
    if( i<0 || i>20)
        
        printf("invalid Entry\n");

        else

        (f[i].name," ");
        
    }


int main(void)
{
      char a;     /* command line input */

    for(i=0; i<20; i++)
    {
                 strcpy(f[i].name, " ");

                 strcpy(f[i].surname," ");

                  strcpy(f[i].number," ");

    }



        printf(" Enter a command\n 'A' : Add an Entry \n 'D' : Delete an Entry\n 'S' : Sort Entries \n 'P' : Print the phone book\n 'Q' : Quit\n\n");



      scanf("%c",&a);

    if(a=='a')
      {

                        Createnew();
      }
     else if(a=='q')
    {
        printf("\nBye\n");    
         return 0;
    }
    else if(a=='d')
    {
    delete();
    }

    else 

    {
        printf("unknown command\n");
    }

    /* if(a=='s')*/

    

}

[Tc Diehl]

Okay so i just copied and pasted

        printf("  Enter a command\n 'A' : Add an Entry \n 'D' : Delete an Entry\n 'S' :  Sort Entries \n 'P' : Print the phone book\n 'Q' : Quit\n\n");
 
 
 
      scanf("%c",&a);
 
    if(a=='a')
      {
 
                        Createnew();
      }
     else if(a=='q')
    {
        printf("\nBye\n");    
         return 0;
    }
    else if(a=='d')
    {
    delete();
    }
 
    else
 
    {
        printf("unknown command\n");
    }

a second time, but that does not seem like the right answer, and doesnt really work because it takes my phone number as the next command

[rags_to_riches]

For, While and Do While Loops in C - Cprogramming.com

[Tc Diehl]

okay, so while loop the whole program until Char a==q and get rid of the if a==q then return 0....

[Tc Diehl]

#include<stdio.h>
#include<stdlib.h>
#include<string.h>

//strcmp
//strcpy

int i;

void Createnew(void);

void delete(void);

struct entry

     {
        char name[12];

        char surname[12];
        
        char number[12];
    

    };

struct entry f[20];



void Createnew(void)
{

       printf("Enter Name\n");

    i=0;

    scanf("%s", f[i].name);

    printf("Enter Surname\n");

    scanf("%s", f[i].surname);

    printf("Enter Phone Number\n");

    scanf("%s", f[i].number);


}

void delete()
    {




    printf("Enter index of entry to delete\n");

    scanf("%i",&i);

    
    if( i<0 || i>20)
        
        printf("invalid Entry\n");

        else

        (f[i].name," ");
        
    }


int main(void)
{
      char a;     /* command line input */

    a=='z';

    for(i=0; i<20; i++)
    {
                 strcpy(f[i].name, " ");

                 strcpy(f[i].surname," ");

                  strcpy(f[i].number," ");

    }

while(a!=='q'){

        printf(" Enter a command\n 'A' : Add an Entry \n 'D' : Delete an  Entry\n 'S' : Sort Entries \n 'P' : Print the phone book\n 'Q' :  Quit\n\n");



      scanf("%c",&a);

    if(a=='a')
      {

                        Createnew();
      }
    
    else if(a=='d')
    {
    delete();
    }

    else 

    {
        printf("unknown command\n");
    }


    /* if(a=='s')*/

    

            }

        printf("\nBye\n");    
         return 0;
}

Tried the while loop, am i using the ! operator wrong?

[stahta01]

"!==" is likely not correct try "!=".

Tim S.

[Tc Diehl]

Thanks dude, its always the simple mistakes

[Tc Diehl]

Okay so i am still having this problem that after i enter name, surname, and number, I get unknown command then the options list then options list agian, and its ready to take new command. Cannot seem to fig;ure out why. Any thoughts?

[Tc Diehl]

Sorry, here is the updated code....

#include<stdio.h>
#include<stdlib.h>
#include<string.h>

//strcmp
//strcpy

int i;

void Createnew(void);

void delete(void);

struct entry

     {
        char name[12];

        char surname[12];
        
        char number[12];
    

    };

struct entry f[20];



void Createnew(void)
{

       printf("Enter Name\n");

    i=0;

    scanf("%s", f[i].name);

    printf("Enter Surname\n");

    scanf("%s", f[i].surname);

    printf("Enter Phone Number\n");

    scanf("%s", f[i].number);


}

void delete()
    {




    printf("Enter index of entry to delete\n");

    scanf("%i",&i);

    
    if( i<0 || i>20)
        
        printf("invalid Entry\n");

        else

        (f[i].name," ");
        
    }


int main(void)
{
      char a;     /* command line input */

    a=='z';

    for(i=0; i<20; i++)
    {
                 strcpy(f[i].name, " ");

                 strcpy(f[i].surname," ");

                  strcpy(f[i].number," ");

    }

    while(a!='q'){

        printf(" Enter a command\n 'A' : Add an Entry \n 'D' : Delete an Entry\n 'S' : Sort Entries \n 'P' : Print the phone book\n 'Q' : Quit\n\n");



      scanf("%c",&a);

    if(a=='a')
      {
     Createnew();
      }
    
        else if(a=='d')
        {
        delete();
        }
    
            else if(a=='p')

                {
                printf("%s\n%s\n%s\n",f[0].name,f[0].surname,f[0].number);
                }
    
            else if(a!='a' || a!='d' || a!='q' || a!='p' ||a!='z' ||a!='s' )

            {
            printf("unknown command\n");
            }


    /* if(a=='s')*/

    

            }

        printf("\nBye\n");    
         return 0;
}

[laserlight]

These suck:

int i;

void Createnew(void);
 
void delete(void);

struct entry f[20];

Why? Because they are unnecessarily global. This makes it harder for you to reason about your program and harder for you to reuse your code (not that you'll need to here, but just saying for the future). Furthermore, a name like f for such an array is really... f'ed up. Such short and undescriptive names are typically only used for loop counters and in generic mathematical computations.

Rather, design your functions to use local variables, and have parameters where necessary. For example:

void create_entry(struct entry *entries, int i); /* Create entry at index i */

Now in the main function:

int main(void)
{
    /* ... */
    struct entry entries[20]; /* 20 should be a named constant instead */
    int entries_size = 0;
    create_entry(entries, size++);
    /* ... */
}

Personally though, I would have create_entry be concerned about creating a single entry:

void create_entry(struct entry *entries);

Then in main the function call will be:

create_entry(&entries[size++]);

But that's up to you. Remember to check that the size does not exceed 20.

[Tc Diehl]

As for the create_entry, i do not know how to use pointers at this time, its next chapter. The rest of what you have said makes alot of sense, i my try and look ahead and see if i might figure out enough about pointers to use in this program as it might actually make it alot easier.

[Tc Diehl]

UGH!!! Still struggling with just getting the bugs out of what i have so far. I have not started on the sorting part of the assignment yet. Anyways, it appears im only storing the last entry and cannot figure out why. Other problems include, the "Unkown Command" coming up when its not needed, and "P" printing my one stored entry and 19 more blank cells. Anyone have any suggestions for these?

#include<stdio.h>
#include<stdlib.h>
#include<string.h>

//strcmp
//strcpy

int i;

void create_entry(struct entry *entries, int i); /* Create entry at index i */

void delete(void);

struct entry

     {
        char name[12];

        char surname[12];
        
        char number[12];
    

    };

struct entry book[20];



void Createnew(void)
{

       printf("Enter Name\n");

    i=0;

    scanf("%s", book[i].name);

    printf("Enter Surname\n");

    scanf("%s", book[i].surname);

    printf("Enter Phone Number\n");

    scanf("%s", book[i].number);


}

void delete()
    {




    printf("Enter index of entry to delete\n");

    scanf("%i",&i);

    
    if( i<0 || i>20)
        
        printf("invalid Entry\n");

        else

        (book[i].name," ");
        
    }


int main(void)
{
      char a;     /* command line input */

    a=='z';

    for(i=0; i<20; i++)
    {
                 strcpy(book[i].name, " ");

                 strcpy(book[i].surname," ");

                  strcpy(book[i].number," ");


    }

    while(a!='q'){

        printf(" Enter a command\n 'A' : Add an Entry \n 'D' : Delete an Entry\n 'S' : Sort Entries \n 'P' : Print the phone book\n 'Q' : Quit\n\n");



      scanf("%c",&a);

    if(a=='a')
      {
     Createnew();
      }
    
        else if(a=='d')
        {
        delete();
        printf("Entry Deleted\n");
        }
    
            else if(a=='p')
                for(book[i].name!=" ";i<20;i++)
                {
                printf("%s\n%s\n%s\n",book[i].name,book[i].surname,book[i].number);
                }
    
            else (a!='a' || a!='d' || a!='q' || a!='p' ||a!='z' ||a!='s' );

            
            
            printf("unknown command\n");

            



    /* if(a=='s')*/
    
            

        }

        printf("\nBye\n");    
         return 0;

}

[Tc Diehl]

So was looking at it, Do i need i to be declared as static variable?

[Tc Diehl]

grrr.... so i tried with i being static, no differnce so then

void Createnew(void)
{

       printf("Enter Name\n");

    i+=i;

and that was even worse then before

[QuantumPete]

Do i need i to be declared as static variable?

That is almost never the correct answer.