CODEWITHSUNDEEP
cpointers
Muhammad Bima Pramadinata
Muhammad Bima Pramadinata

Reputation: 139

unknown type of struct in parameter function C when using Struct type data in parameter

how to pass struct type data using parameters to another function ? i have already create a global struct but i think i've miss something 

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

struct Stuff
{
    int id;
    String name[20];
}

// call another function
int myFunctionInsert(Stuff *stuff);

int main()
{
    struct Stuff *stuff[20];
    myFunctionInsert(*stuff);
}

int myFunctionInsert(Stuff *stuff)
{
    int x;
    for(x = 0; x < 25; x++){
        stuff[x].id = x;
        stuff[x].name = 'stuff';
    }
}

so my purpose is when i already call the myFunctionInsert, the struct data same as i was input in that function.

for example, when i call myFunctionShow (which is i'm not write in) the data show should be like this 

id   : 1
name : stuff

// until 25

when i tried my code above, i got an error

Unknown type name 'Stuff' (in line i call myFunctionInsert(Stuff *stuff))

any help will be appreciated

thanks

Upvotes: 1

Views: 1332

Answers (2)

sg7
sg7

Reputation: 6298

The problem is not only with lack of typedef. Also memory will be smashed since for(x = 0; x < 25; x++){ crosses the boundary of 

struct Stuff *stuff[20];

Also stuff[x].name = 'stuff'; will not fly. You mean "stuff". Notice that there is no String type in C language.

The working version of the program where size of the passed array of structures is specified may look like this:

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

    typedef struct stuff
    {
        int id;
        char name[20];
    }Stuff;

    // call another function
    int myFunctionInsert(Stuff *stuff, int len);

    int myFunctionInsert(Stuff *stuff,int len)
    {
        int x;
        for(x = 0; x < len; x++){
            stuff[x].id = x;
            strcpy( stuff[x].name, "stuff");

            printf("stuff %i id=%d  name=%s\n", x, stuff[x].id, stuff[x].name );
        }
    }

    int main()
    {
        Stuff sf[25];
        myFunctionInsert(sf,5); // init 5 structures
        return 0;
    }

OUTPUT:

stuff 0 id=0  name=stuff
stuff 1 id=1  name=stuff
stuff 2 id=2  name=stuff
stuff 3 id=3  name=stuff
stuff 4 id=4  name=stuff

Upvotes: 3

mschmidt
mschmidt

Reputation: 2790

The type you defined is struct Stuff not Stuff. Hence:

// call another function
int myFunctionInsert(struct Stuff *stuff);

Alternatively use typedef:

typedef struct Stuff
{
    int id;
    String name[20];
} Stuff;

Upvotes: 4

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