The Big-O notation

Identify and explain the Big-O notation for given;

1. public void function(int arr[], int n)
   {
   for (int i = 0; i < n; i++)
   {
   System.out.println(arr[i]);
   }
   for (int i = 0; i < n; i++)
   {
   for (int j = 0; j < n; j++)
   {
   System.out.println (arr[i] + arr[j]);
   }
   }
   }
2. for (int i = 0; i < n; i++) {
   for (int j = 0; j < n*n; j++) {
   System.out.println(“Hello”);
   }
   }
3. public static int countIt (int n) {
   int count = 0;
   for (int i = n; i > 0; i /= 2)
   for (int j = 0; j < 10; j++)
   count += 1;
   return count;
   }