Thread: Using a multidimensional array to store a list of first and last names

3. Create a program that allows a user to enter up to five names
of friends. Use a two-dimensional array to store the friends’
names. After each name is entered, the user should have the
option to enter another name or print out a report that shows
each name entered thus far.

I have some code that I posted on here a long time ago its a close thread now anyway I'm just wondering how to print out say 5 names first and last here's the old code

Code:

#include <stdio.h>
#include <stdlib.h>
 
int main()
{
 
    int i = 0;
    char *iName[2][15] =  {'\0'};
    int iChoice = 0;
 
 
    while(iChoice != 3)
    {
        system("cls");
        printf("\n1\tEnter a name");
        printf("\n2\tPrint Report");
        printf("\n3\tQuit");
        printf("\n\n\tEnter a Choice: ");
        scanf("%d", &iChoice);
 
        if(iChoice == 1)
        {
            system("cls");
            printf("\n\tEnter a name: ");
            scanf("%s %s", iName[0],iName[1]);
        }
        else if(iChoice ==2)
        {
            system("cls");
            for (i = 0; i <= 3; i++)
              printf("%s %s\n",iName[i],iName[i]);
            break;
        }
    }

    system("Pause");
    return (0);   

 
}

Code:

char *iName[2][15] =  {'\0'}; // Drop the '*' you can do this by having just a 2d array of characters

Ask yourself how you would enter in 5 integers into an array.. You would use a loop. Well this is the same type of deal. You are going to need more rows in your array if you want to be able to enter in 5 names. Right now you can only enter in 2 names.

Originally Posted by camel-man

Code:

char *iName[2][15] =  {'\0'}; // Drop the '*' you can do this by having just a 2d array of characters

Ask yourself how you would enter in 5 integers into an array.. You would use a loop. Well this is the same type of deal. You are going to need more rows in your array if you want to be able to enter in 5 names. Right now you can only enter in 2 names.

Eh, the two is for first name and last name. The 15 is the number of names.

The fun part is that we have a two-dimensional array of char pointers, which currently point to nowhere. Memory will have to be allocated for each name before things can actually be stored.

Code:

char *iName[2][15] =  {'\0'};

What would this be considered? A 2d array of all pointers to char? Does that mean that there are 30 dangling pointers to type char?

maybe this will help you,

char *name[];

string constant in indexing array.

how would I allocated memory for the names to be stored the problem statement wants me to use a multidimensional array so loserone I don't want to use a single dimensiion
can you guys use laymens terms that I can understand hee hee

I was just kidding I somewhat understand what you guys are talking about

I plan on changing the for loop around thats not permanent

I still suggest you go with a 2d array rather than a 2d array of pointers. This way you will eliminate the need for dynamic memory allocation which you probably have not gone over yet.

Do you mean like this

Code:

#include <stdio.h>
#include <stdlib.h>
 
int main()
{
 
    int j = 0;
    int i = 0;
    char iName[2][15] =  {'\0'};
    int iChoice = 0;
 
 
    while(iChoice != 3)
    {
        system("cls");
        printf("\n1\tEnter a name");
        printf("\n2\tPrint Report");
        printf("\n3\tQuit");
        printf("\n\n\tEnter a Choice: ");
        scanf("%d", &iChoice);
 
        if(iChoice == 1)
        {
            system("cls");
            printf("\n\tEnter a name: ");
            scanf("%s", &iName[0]);
        }
        else if(iChoice ==2)
        {
            system("cls");
            
              for (i = 0; i <= 5; i++)
                printf("%s\n",iName[i]);
            break;
        }
    }

    system("Pause");
    return (0);   

 
}

This way also doesn't give me the correct print out its suppose to be john Wayne an john Mayer this is the result


Mayer



τ◄@

Press any key to continue . . .

1. This declaration:
   Code:

   char iName[2][15]

   gives you two names of fourteen characters each. You are trying to store four names (John, Wayne, John, and Mayer) and reusing slot 0 each time; hence you will only end up with one name in the list. You will need to keep track, one way or another, of where you are in the list and use that number when inserting names.
2. If you go with array-of-char (instead of array-of-char-*) then your two-dimensional array is really just a one-dimensional array of strings (since a one-dimensional array-of-char is itself just a single string). If you want a string for last name and a string for first name, you'll need another dimension.
3. As a follow-up, if you do go with the entire name in one slot, then you cannot use %s to read in the names, since it will stop on a space -- check up on your other input methods. If you do go with separate slots for first names and last names, you'll have to decide what you want to do with Robert Penn Warren.