array questions

I have the following simplified code.

Code:

---

void TestChannels(int *Chan) {
  int x;

  for (x=0; x<9; x++) {
    Chan[x] = x * 2;        // Problem is here
  }
}

int main() {
  int  Channel[9];
  int x;

  //Initialization
  for (x=0; x<9; x++) {
    Channel[x] = 0;
  }

  TestChannels(Channel);

  for (x=0; x<9; x++) {
    printf("Channel %d = %d", x, Channel[x]);
  }
}

---

My question is, within the function, how do I refer to the individual elements of Channel?

And what is wrong with the code as you have it?

--
Mats

Your use of Chan[x] is correct. However, I suggest adding a parameter for the size of the array to the TestChannels function.

Note that if you want to do zero initialisation of the array, this would suffice:

Code:

---

int Channel[9] = {0};

---

You can then dispense with the loop that sets each element of Channel to 0.

If you expected this:

Channel 0 = 0Channel 1 = 2Channel 2 = 4Channel 3 = 6Channel 4 = 8Channel 5 = 10Channel 6 = 12Channel 7 = 14Channel 8 = 16

Then I don't understand how you are having a problem; there is nothing wrong with your code. One tip, tho: you can initialize all the elements to zero this way:

Code:

---

int  Channel[9]={0};

---

Which it's not particularly necessary in your code anyway, since the entire array gets written into by TestChannels().

[edit] you know what they say about great minds.

Hmmm... Well nothing is wrong... I simplified the actual code I had that wasn't working... I will analyze and get back...

and thanks for the intialization tip

What about this... this is more how my original was structured...

Code:

---

void VerifyChannels(int *Chan) {
  int x;

  for (x=0; x<9; x++) {
    Chan[x] = x * 2;        // Problem is here
  }
}
 
void TestChannels(int *Chan) {
  VerifyChannels(&Chan);
}

int main() {
  int  Channel[9];
  int x;

  //Initialization
  for (x=0; x<9; x++) {
    Channel[x] = 0;
  }

  TestChannels(Channel);

  for (x=0; x<9; x++) {
    printf("Channel %d = %d", x, Channel[x]);
  }
}

---

My error was the & in VerifyChannels(&Chan); It should not have been there.

Code:

---

void TestChannels(int *Chan) {
  VerifyChannels(&Chan);
}

---

This should AT LEAST give you a warning for incompatible pointer types.

--
Mats