CODEWITHSUNDEEP
cpointersstruct
Avinash
Avinash

Reputation: 11

Structure declaration with a pointer to it

I am studying structures in C from K&R book and encountered this:

struct{
    int len;
    char *str
} *p;

I am confused by this, because where the name of the struct variable should be, they have given a pointer *p. Can anyone please help me here? What does this declaration mean?

Upvotes: 1

Views: 72

Answers (1)

CodeMonkey
CodeMonkey

Reputation: 12424

This declaration is a pointer to a struct which is composed of 2 fields — an int and a char*. This struct doesn't have a name and if you want to declare another pointer of the same struct, you will have to write it again.

Notice you can write something like this:

struct MyStruct {
int data1;
char data2;
};

This will define a new struct type which you can use later like this to declare a variable: struct MyStruct myVar;. The difference from what you wrote is that this struct doesn't declare a new variable but a new type since the struct in my example has a name and yours does not.

Another option is to use a typedef and give this struct a name and then you can use the name you have given it to declare more variables of that type.

You can read more about it at http://en.wikipedia.org/wiki/Typedef in the "Simplifying a declaration" section.

Upvotes: 3

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