Arrays

[aamirsherkhan]

hi
Can anyone tell me how can i return a array of three integers form a function;

     
int funtion()
{
int array[]={ 2,3,4 };

return array[];}

will it work

[laserlight]

You cannot return an array from a function. What is the purpose of this function? Depending on its purpose, you could say, assign to an array that is passed (as a pointer) to this function.

[C_ntua]

This is the way you "return array". As laserlight said you return the pointer:

int funtion()
{
  int array[]={ 2,3,4 };

  return array;
}

But keep in mind that this should be WRONG. You will be returning a local variable. I mean array is a local variable for function() so the memory is allocated when calling function() and freed when you leave function() so you cannot return it. If you wanted the above you would have to use malloc(). Or pass the array as a parameter to the function as this:

int funtion(int *array)
{
  array[]={ 2,3,4 }; //not sure if this would work

  return array;
}

Generally there are no real arrays in C. Keep in mind that array[i] means *(array+i), thus saying the value of the memory that is shown by the pointer array plus i spaces of memory.

[QuantumPete]

array[]={ 2,3,4 }; //not sure if this would work

Nope it wouldn't. That's an initializer list and can (as the name suggests) only be used at the initialization stage, i.e. when the variable is defined.

QuantumPete

[Elysia]

int funtion()
{
  int array[]={ 2,3,4 };

  return array;
}

Nope, this would be wrong.
int[3] != int
So essentially, you are returning an incorrect type, as well as a local variable as you describe.
Also, when passing an array to a function, ALWAYS pass the array's size!

void funtion(int* array, int size)
{
  if (size < 3)
    /* ERROR: Too small buffer */;
  int array2[] = { 2, 3, 4 };
  memcpy(array, array2, sizeof(array2));
}

[C_ntua]

int funtion()
{
  int array[]={ 2,3,4 };

  return array;
}

Nope, this would be wrong.
int[3] != int

Right. So you would need (see the *):

int * function(...) {...}

[Elysia]

Yes, that would work.
Only the local variable problem left that you mentioned