C中结构中的字符串数组

Question

Say we have,

typedef struct{
    char* ename;
    char** pname;
}Ext;

Ext ext[5];

What I am trying to do is to populate the data as following:

ext[0].ename="XXXX";
ext[0].pname={"A", "B", "C"};  // and so on for the rest of the array

-- I am pretty sure this is not the right way of doing this because I am getting errors. Please let me know the correct way to do this. Thanks.

Answer 1

The first assignment is correct.

The second one is not. You need to dynamically allocate the array:

ext[0].pname = malloc( sizeof(char*) * 5 );
ext[0].pname[0] = "A";
ext[0].pname[1] = "B";
//and so on
//you can use a loop for this

Answer 2

You don't mention what compiler you are using. If it is C99-compliant, then the following should work:

   const char *a[] = {"A", "B", "C"}; // no cast needed here
   const char **b;
   void foo(void) {
       b = (const char *[]){"A", "B", "C"}; // cast needed
   }

Your arrays being within a typedef'd struct is irrelevant here.

---

Edit: (nine years later). My answer is wrong: the compound literal in foo() is created on the stack (aka automatic storage), and so the above code is incorrect. See eg Lifetime of referenced compound array literals , and see Initializing variables with a compound literal .

In contrast, this code snippet is fine:

   const char *a[] = {"A", "B", "C"}; // no cast needed here
   const char **b = (const char *[]){"A", "B", "C"}; // cast needed