C声明char *数组

Question

I thought you could declare an array, and then later initilze it.

Like so

char* myArray[3];


//CODE INBETWEEN 

myArray[3] = {

            "blah",
            "blah",
            "blah"};

Answer 1

Nope, you can only initialize an array when you first declare it. The reason is that arrays are not modifiable lvalues.

In your case:

char *array[] = {"blah", "blah", "blah"};

You don't need to specify the size, but you can if you want. However, the size can't be less than 3 in this case. Also, the three strings are written to read-only memory so something like array[1][2] = 'c' to change the 2nd "blah" to "blch" will normally result in a segfault.

Answer 2

As others have said you can only use initialisers when the variable is declared. The closest way to do what you want is:

char *myArray[3];

/* CODE INBETWEEN */

{
    static const char *tmp[3] = {
            "blah",
            "blah",
            "blah" };
    memcpy(myArray, tmp, sizeof myArray);
}

Answer 3

Yes, you can declare an array and then later initialize it.
However, there is an exception here.
You are declaring a (which worked fine).
And, then you are .

That is where the problem starts.
Constant strings are just compiler primitives that do not get any addressable memory location in the way you have used them. They can be assigned right at the array initialization time (as Mike has shown); that will instruct the compiler to allocate them as constants available at run-time and allow an initialization when the scope of myArray starts.

---

What you have tried would have worked well with

int numberArray[3];
// code here
numberArray[0] = 1;
numberArray[1] = 2;
numberArray[2] = 3;

It helps to note that a character pointer and a string instance are two different entities; the first can point to the second.

Answer 4

You thought wrong. Initialization is only possible at declaration. After that, you can only assign individual values.

Answer 5

It's an initializer expression. Can't have that code in between, got to be used on the line withe declaration.

Answer 6

It's not exactly clear which real world problem you're trying to solve, here...

I thought you could declare an array,

... that is possible in so many ways, but for the sake of this question I want to focus on declaring an array inside of a struct .

struct my_struct {
    char *my_array[3];
};

and then later initilze it.

Like so

struct my_struct fubar;
fubar = (struct my_array) { { "hello", "world" } };

Technically speaking this is initialisation of a different array (within an anonymous object) followed by an assignment of the entire struct . It might be useful to solve your real world problem (whatever that is)... but hopefully it will ultimately be useful for someone else later on to know that you can assign struct s with arrays inside of them...