How do I check the contents of an array?

Question

I want to check if a char array contains all '0's.

I tried this, but it doesn't work:

char array[8];
// ...
if (array == {'0','0','0','0','0','0','0','0'})
   // do something

How do I do this?

Answer 1

This

array == {'0','0','0','0','0','0','0','0'}

is definitely wrong, and surely not compiling.

You can compare the values with memcmp() like this

int allZeroes = (memcmp(array, "00000000", 8) == 0);

Answer 2

In fact

array == {'0','0','0','0','0','0','0','0'}

is not allowed, you cannot compare arrays like this. Rather, do it in a loop:

int row_is_all_zeroes(char arr[8])
{
  for (int i = 0; i < 8; i++)
  {
    if (arr[i] != '0')
      return 0;
  }
  return 1;
}

If you want a more elegant solution, have a look at iharob or Sourav's answers

Answer 3

{'0','0','0','0','0','0','0','0'}

is called (and used as) a brace enclosed initializer list. This cannot be used for comparison anywhere.

You can make use of memcmp() to achieve this in an elegant way.

Pseudo-code

if (!memcmp(array, "00000000", 8))
{
   break;
}