How can i initialize global struct in c?

Question

I tried to make a program (in VS 2019) that prints out each values of certain characters, but it doesn't seem to work well. When executed, it prints out the number '0', regardless of which I entered.

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

typedef struct value //Value for each characters
{
    char tier;
    int weight;
    float airspeed;
    float fallspeed;
    float fastfall;
    float dash;
}V;

 V mario; //I set 'Mario' as a variable.
 V mario; tier = 'A';
 V mario; weight = 98;
 V mario; airspeed = 1.208f;
 V mario; fallspeed = 1.5f;
 V mairo; fastfall = 2.4f;
 V mario; dash = 1.76f;

int main(void)
{
    printf("%d", mario.weight); //mario.weight is '98'.
    return 0;
}

I thought that "mario.weight" would be printed as '98', but when I executed it printed '0'.

Did you note a dozen warnings your compiler complained about? `V mario; weight = 98` does something very different than `mario.weight = 98`... Let's not even talk about `mairo`... — Amadan, Mar 09 '20 at 04:51
@rsonx the OP is using VS which doesn't have `-Wall`. \@김도영 go to project setings https://learn.microsoft.com/en-us/cpp/build/reference/compiler-option-warning-level?view=vs-2019 — phuclv, Mar 09 '20 at 06:28

srilakshmikanthanp · Accepted Answer · 2020-03-09T10:51:58.337

You can do something like

     V mario={'A',98,1.208f,1.5f,2.4f,1.76f};

or

     V mario={.tier='A',.weight=98,.airspeed=1.208f,.fallspeed=1.5f,.fastfall=2.4f,.dash=1.76f};

1)In you code

 V mario; //I set 'Mario' as a variable.
 V mario; tier = 'A';
 V mario; weight = 98;
 V mario; airspeed = 1.208f;
 V mario; fallspeed = 1.5f;
 V mario; fastfall = 2.4f;
 V mario; dash = 1.76f;

Here all

     V mario;

goes to Tentative definitions and defaults to 0.

2)Here

     tier,weight,airspeed,fallspeed,fastfall,dash.

all are defaults to int you can check this by changing mario.weight to weight in printf it will print 98.

3)global variable can initialized when it is defined but you can not do this because it is not initialization

V mario; //I set 'Mario' as a variable.
mario.tier = 'A';
mario.weight = 98;
mario.airspeed = 1.208f;
mario.fallspeed = 1.5f;
mario.fastfall = 2.4f;
mario.dash = 1.76f;

but you can do this in main, if you want to know why this is not possible see this

Why can't I assign values to global variables outside a function in C?

for info about Tentative definitions see this https://www.ibm.com/support/knowledgecenter/en/ssw_ibm_i_71/rzarg/tentative_defn.htm

thank you! the code is working well. i made as `V mario; weight` instead of `mario.weight`, because VS thought it was an error. why is that? — 김도영, Mar 09 '20 at 09:28

How can i initialize global struct in c?

1 Answers1