Thread: Phonebook search without cs50.h library ?

Hi,

Iam using different tutorials and sadly the lecture from Harvard on YT always uses a custom made "cs50.h" library which in the end just complicate things because I have to figure then things out myself, or is everyone using it ? I guess not so I obviously dont want to rely on it.

Well here is a simple phonebook search, at least Iam not getting any errors anymore but the code also doesnt print out anything, any help would be appreciated.

Code:

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

typedef struct
{
    char name[20];
    char phone[20];
}
Phonebook;

int main()
{

Phonebook people[2];

Phonebook kevin;
strcpy(kevin.name, "Kevin Schmidt");
strcpy(kevin.phone, "827123");

Phonebook maik;
strcpy(maik.name, "Maik Mueller");
strcpy(maik.phone, "67322188");

char find[20];
printf("Name to find ?: ");
scanf("%s", find);

for(int i = 0; i < 2; i++)
{
    if(strcmp(people[i].name, find) == 0)
    printf("Found %s\n", people[i].phone);
}
return 0;
}

But maybe the whole thing is wrong I have no clue, thanks in advance as always :).

> strcpy(kevin.name, "Kevin Schmidt");
You want to use people[0].name etc to initialise both elements of your array.

> or is everyone using it ?
Nobody outside of whatever course that's for even knows or cares what's in it.

If you can manage to do what you want with only the standard libraries, you're in good shape.

cs50.c (and its header file cs50.h) consists of 6 functions for entering a character, string, int, long, float, or double, with a prompt and some error (e.g. range) checking. It is not important.

Your code has another problem besides not putting anything in the people array.
Using the %s format with scanf will stop reading input at the first space, so if the input was Kevin Schmidt it would only read Kevin. The format %[^\n] will read up to the end of the input line (it basically says to keep reading characters until it encounters a newline character).

Thanks for your time and help but I cant figure it out, it just wont work. If I initiliaze with "people[0]" etc. which I also tried before then the variables "Maik, Kevin" are unused.

I also dont understand what you mean by "%[^\n]", that will give an error. And if I put "%s[^\n]" it will do the same as before (at least I think so).

I guess I cant see the forest full of trees, maybe I should move on to something else for a while :/.

I thought I have to replace my "strcpy ..." code with the "people..." code but still it wont print out anything in the end. If it works for you then maybe my IDE or compiler is faulty ? I just get a blank line in the end even tho the names exist.

My IDE also puts the "%" from the "scanf" function in red, no clue why.

Guess I will reinstall everything and see if it fixes it. Thanks for the help.

@EmVee, the s after %[^\n] is incorrect. Also, you don't need the kevin and maik objects. You can assign directly to people.

Code:

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

typedef struct
{
    char name[20];
    char phone[20];
}
Phonebook;

int main()
{
    Phonebook people[2];

    strcpy(people[0].name, "Kevin Schmidt");
    strcpy(people[0].phone, "827123");

    strcpy(people[1].name, "Maik Mueller");
    strcpy(people[1].phone, "67322188");

    char find[20];
    printf("Name to find: ");
    scanf("%[^\n]", find);

    for (int i = 0; i < 2; i++)
    {
        if (strcmp(people[i].name, find) == 0)
            printf("Found %s\n", people[i].phone);
    }

    return 0;
}