complexity of hashmap code example

Example 1: java hashmap time complexity

On the other hand, a HashMap has an average time complexity of O(1) 
  for put() , contains() and remove() operations. 
  The worst-case time complexity for those operations is O(log n) 
  since Java 8, and O(n) before that. Space-complexity wise, both
  have a complexity of O(n)

Example 2: java hashmap time complexity

On the other hand, a HashMap has an average time complexity of O(1) for put() , contains() and remove() operations. The worst-case time complexity for those operations is O(log n) since Java 8, and O(n) before that. Space-complexity wise, both have a complexity of O(n)