Defining a new instance of a struct

Question

I tried typing the following code in a simple C project, but it keeps saying that MyStruct is undefined – unless I add struct before every MyStruct (i.e. struct MyStruct my_struct; which just feels wrong?).

struct MyStruct {
    int my_int;
}

int main() {
    MyStruct my_struct;
    my_struct->my_int = 1;

    return 0;
}

https://stackoverflow.com/questions/47555734/why-must-the-struct-keyword-precede-struct-instances-in-c?rq=1 — Mat, Apr 26 '20 at 19:40

score 1 · Accepted Answer · answered Apr 26 '20 at 19:43

1

It’s not wrong, it’s the way C works. Type name is struct MyStruct (it would be simply MyStruct in C++). If you feel that inconvenient, make a typedef, like:

typedef struct MyStruct { ... } MyStruct;

That may or may not be considered a good practice, though.

Also note that a struct (but not a typedef) and a function can have the same name (without the struct prefix). sigaction is a real-word example of that.

answered Apr 26 '20 at 19:43

numzero

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6
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Very useful! I guess I'm too used to C++. This is for a C assignment, though, so I guess getting used to writing `struct MyStruct` would be better practice to remind myself of how C differs from C++. – Matt Apr 26 '20 at 19:45

Defining a new instance of a struct

1 Answers1