Nested function or calling function in a function

Question

So, I'm not sure how to start, so I'll start with some code:

    int main()
{
    system("cls");
    printf( "1. D4\n" );
    printf( "2. D6\n" );
    printf( "3. D8\n" );
    printf( "4. Exit\n" );
    printf( "Selection: " );
    scanf( "%d", &input );
    switch ( input ) {
        case 1:            
            roll_d4();
            break;

First off, I have this, and when I pick a selection, it works to get me to the function I wanted. So when I get to the D4 function, I have this:

void roll_d4() {
system("cls");
printf("How many D4 do you want to roll?\n");
printf("Enter a number 1-20");
printf("\nSelection: ");
scanf("%d", &input);
switch (input){
    case 5:
    exit(0);
    d4_number();
}

Now, every time I try to run this, it doesn't like the d4_number(); and says it's an implicit declaration. I'm just trying to let you pick a selection and have it go to the next part in the code, in this case a function that will actually roll a die rather than being a menu like this one. But doing it this way isn't working, and I'm at a loss at what to do.

Edit: Code addition. Here's the full program:

#include <stdio.h>
#include <ctype.h>
#include <time.h>
#include <stdlib.h>
#include <stdbool.h>
#include<string.h>
#include<process.h>
#include<conio.h>
#include<ctype.h>
char response;
    int sum = 0;
    time_t t;
    int result;

    int die_d4_1 = 0;
    int die_d4_2 = 0;
    int die_d4_3 = 0;
    int die_d4_4 = 0;
    int die_d4_5 = 0;
    int input;

void roll_d4() {
    system("cls");
    printf("How many D4 do you want to roll?\n");
    printf("Enter a number 1-20");
    printf("\nSelection: ");
    scanf("%d", &input);
    switch (input){
        case 5:
        exit(0);
        d4_number(0);
    }
}
void roll_d6()
{
    printf( "How many D6 do you want to roll?" );
}
void roll_d8()
{
    printf( "How many D8 do you want to roll?" );
}

void d4_number(){
    printf("How many d4 do you want to roll?");
}

int main()
{
    system("cls");
    printf( "1. D4\n" );
    printf( "2. D6\n" );
    printf( "3. D8\n" );
    printf( "4. Exit\n" );
    printf( "Selection: " );
    scanf( "%d", &input );
    switch ( input ) {
        case 1:            /* Note the colon, not a semicolon */
            roll_d4();
            break;
        case 2:          
            roll_d6();
            break;
        case 3:         
            roll_d8();
            break;
        case 4:        
            printf( "Thanks for playing!\n" );
            break;
        default:            
            printf( "Bad input, quitting!\n" );
            break;
    }
    getchar();

}

It's obviously very incomplete, but I'm just trying to solve this problem before adding more.

It doesn't look like you've defined your d4_number() function. (If you have, then you haven't shown us all your code.) — Keith Thompson
– Keith Thompson, Commented Feb 16, 2017 at 0:34

Malcolm McLean · Accepted Answer · 2017-02-16 00:32:41Z

2

You need to give d4_number() a prototype, before the call, so the compiler know what arguments it takes and what it returns. Otherwise it still links (for historical reasons) and assumes it returns an int.

answered Feb 16, 2017 at 0:32

Malcolm McLean

6,4201 gold badge19 silver badges18 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

MaxZoom · Accepted Answer · 2017-02-16 00:49:23Z

1

If you take a closer look at this code

switch (input){
    case 5:
    exit(0);
    d4_number(0);
}

you can notice that before d4_number function there is an exit function invoked. In that case d4_number function has never a chance to execute because the whole program stops and exits with 0 as a return code.

Other issue is that d4_number function definition does not accept any arguments, but in statement d4_number(0) there is one extra parameter passed.

edited Feb 16, 2017 at 0:49

answered Feb 16, 2017 at 0:39

MaxZoom

7,7635 gold badges30 silver badges45 bronze badges

1 Comment

hego64 Over a year ago

I had forgotten that wasn't commented out. When I remove it and try to compile I get the same error: "In function 'roll_d4': case_break.c:32:3: warning: implicit declaration of function 'd4_number' [-Wimplicit-function-declaration] d4_number();"

hego64 · Accepted Answer · 2017-02-16 00:49:15Z

0

Okay, I feel like an idiot. All I had to do was move the declaration:

        void d4_number(){
    printf("How many d4 do you want to roll?");
}

above

void roll_d4() {
system("cls");
printf("How many D4 do you want to roll?\n");
printf("Enter a number 1-20");
printf("\nSelection: ");
scanf("%d", &input);
switch (input){
    case 5:
    d4_number(0);
}

so that it was declared before calling...I feel really dumb for this, but thanks everyone for the quick responses!

answered Feb 16, 2017 at 0:49

hego64

3641 gold badge8 silver badges23 bronze badges

Collectives™ on Stack Overflow

Nested function or calling function in a function

3 Answers 3

Comments

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related