absolutely it won’t return false
because the condition in both for loops 9 < j
is always false
it should be:
public static boolean validity(int array[][], int array2[][])
{
for(int j = 0; j < 9; j++){
for(int i=0; i < 9; i++){
if (array2[j][i] != array[j][i]&& array2[j][i] == 0){
return false;
}
}
}
return true;
}