'fgets' runs after 'printf'

Question

I'm slowly learning C. I read this page about input and output dealing with strings here: http://www.cprogramming.com/tutorial/c/lesson9.html

In the last code example, fgets is used to get and assign the input to a variable to the char array name. I tried implementing something similar in my own program.

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

/* This is my very first C program! */

bool test=true;

/* Function Prototypes */

int mult(int x, int y);

/* Structures */

struct Person {
    int age;
    char name[256];
};

/* Complicated Array ;P */

struct Person *FirstPeriod[22];
char FakeString[100];

void PracticeStrings()
{
    int i;
    fgets(FirstPeriod[0]->name, 256, stdin);
    for (i=0;i<256;i++)
    {
            if (FirstPeriod[0]->name[i]=='\n')
                FirstPeriod[0]->name[i]='\0';
    }
    printf("\n\nHello Student 0: %s",FirstPeriod[0]->name);
}

int main()
{
    struct Person DadeLamkins;
    DadeLamkins.age=16;
    int numb;
    int x;
    int *numb_address=&numb;
    numb_address=malloc(sizeof(*numb_address));

    FirstPeriod[0]=&DadeLamkins;

    if (true)
        printf("-__- \n\n");

    printf("Please enter a number: ");
    scanf("%d", &numb);
    switch (numb) {
        case 0:
            printf("Dude, 0 is lame...\n");
            break;
        case 7:
            printf("Dude, 7 is my favorite number!\n");
            break;
        default:
            printf("You entered %d\n", numb);
            break;
    }
    for (x=0;x<numb+1;x++) {
        printf("\n::# %d",mult(x,2));
    }
    printf("\n\n%d",numb_address);
    free(numb_address);
    numb_address=0;
    PracticeStrings();
    getchar();
    return 0;
}

int mult (int x, int y)
{
    return x*y;
}

The PracticeStrings function on line 26 is the issue currently. When I compile, it displays Hello Student 0: before accepting the input (from fgets). I'm using Code::Blocks to compile.

Any help would be appreciated!

Edit...

Hahaha, yes, I understand that my program is inefficient and very silly. As you can tell, it doesn't really accomplish much. It is mostly just something to shove what I'm currently learning and try to apply things without actually rewriting the code examples (what do I learn if I copy word for word?). Anyways, thanks for the help! I guess that does make sense! It is too bad that my tutorials didn't mention that, I'm sure it is something that just takes a little bit of a higher understanding. I'm sure that the tutorial writer didn't expect anyone to mix the functions in the way I did.

Thanks a ton guys! Hopefully I can get used to this. I've done lots of scripting and plenty in the .net languages, hopefully I can add C to this list :)

Answer 1

It is because when you read the number:

scanf("%d", &numb);

stdin still has \n left in the buffer. So when you call PracticeStrings() and subsequently:

fgets(FirstPeriod[0]->name, 256, stdin);

You read \n and end up with

FirstPeriod[0]->name[i] == '\0';

---

Further, as you are learning, learn to validate :)

I.e.:

if ((foo = malloc(blah)) == NULL) {
    ... err ...

And even more critical:

if (scanf(..) != number_of_items_i_want) {
    ... did not get a number, or what ever I wanted ...

etc.