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basic issues with struct

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Join Date: Apr 2008

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MaestroRage MaestroRage is offline

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basic issues with struct

Aug 31st, 2009

I'm having some trouble using struct which I can't seem to figure out. it seems to be following all the examples perfectly, i've tried to break it down to it's simplest block and nothing. Can somebody please tell me why this won't compile?

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#include <stdio.h>
 
typedef struct a{
	char a[25][12]={"a", "b", "c"};
	int b[12]={10, 5,1};
};
 
struct test{
	char a[25][12]={"a", "b", "c", "d"};
	int b[12]={2, 1,1,3};
	int c[12]={1,1,1,2};
};
 
int main (){
 
 
	return 0;
}
#include <stdio.h>

typedef struct a{
	char a[25][12]={"a", "b", "c"};
	int b[12]={10, 5,1};
};

struct test{
	char a[25][12]={"a", "b", "c", "d"};
	int b[12]={2, 1,1,3};
	int c[12]={1,1,1,2};
};

int main (){


	return 0;
}

I get this error
error C2143: syntax error : missing ';' before '='

but this error doesn't make much sense to me.

TIA.

Last edited by MaestroRage; Aug 31st, 2009 at 6:30 pm.

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Join Date: Nov 2005

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dwks

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Re: basic issues with struct

Aug 31st, 2009

You can't assign anything inside a structure declaration. A structure declaration just defines a type. It's like a blueprint; you're telling the compiler, "if I ask you to create a Something, this is what I want it to look like." An example of a structure declaration would be

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struct Something {
    int x, y;
    double zoom;
};
struct Something {
    int x, y;
    double zoom;
};

When you declare an instance of a structure, you're actually using memory. Here I create a variable of type Something:

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struct Something variable;

Since this is a variable, it can be initialized as you were doing above.

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struct Something variable = {1, 2, 5.0};
struct Something variable = {1, 2, 5.0};

Of course, you can always do it manually too.

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 C Syntax (Toggle Plain Text) 
struct Something variable;
variable.x = 1;
variable.y = 2;
variable.zoom = 5.0;
struct Something variable;
variable.x = 1;
variable.y = 2;
variable.zoom = 5.0;

Just think of a structure as a new type, like int or char -- not a built-in type, but rather a type you've defined in terms of built-in types (or other structures).

dwk

Seek and ye shall find.

"Only those who will risk going too far can possibly find out how far one can go."
-- TS Eliot.

"I have not failed. I've just found 10,000 ways that won't work."
-- Thomas Alva Edison

"The only real mistake is the one from which we learn nothing."
-- John Powell

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Join Date: Apr 2008

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MaestroRage MaestroRage is offline

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Re: basic issues with struct

Aug 31st, 2009

aaah!

I knew it had to be something simple like that. I'm having a terrible off day I can't believe I didn't see that.

Thanks a lot for the quick and very informative post!