Thread: Usage of double pointers

Well, take a look at these warnings:

Code:

test.c: In function ‘main’:
test.c:5:16: warning: initialization from incompatible pointer type [-Wincompatible-pointer-types]
  char **ch = { "abc", "def" };
                ^
test.c:5:16: note: (near initialization for ‘ch’)
test.c:5:23: warning: excess elements in scalar initializer
  char **ch = { "abc", "def" };
                       ^
test.c:5:23: note: (near initialization for ‘ch’)

I haven't come across this problem before, but it seems you can't directly assign the address of an initialization list to a variable, as it probably doesn't have one yet.

Originally Posted by krkr

So we can't initialize a double pointers?

You can, but not like this. For example, you can do:

Code:

const char *ch2[] = { "abc", "def" }; // ch2 has to be stored somewhere, of course
const char **ch = ch2;

or if you'd like to go the dynamic allocation route:

Code:

const char **ch = malloc(sizeof(char*)*2);
ch[0] = "abc";
ch[1] = "def";
...
free(ch);

or you could even scratch this double-pointer idea and try something else, like a multi-string:

Code:

const char *ch = "abc\0def\0";
// This needs extra code for some things though