Data Structures

ArrayList

• add(element) - appends an element to the list
• addAll(elements) - appends an array of elements to the list
• get(index) - gets element by index from the list
• contains(element) - checks if a given element exists in the list
• size() - returns the number of elements in the list
• remove(element) - removes an element from the list
• removeAt(index) - removes an element at a given index from the list
• clear() - removes all of the elements from the list
• toArray() - returns the values from the list as an array

LinkedList

• add(element) - appends an element to the list
• addAt(index, element) - adds an element at a given index in the list
• addFirst(element) - adds an element at the beginning of the list
• addLast(element) - adds an element at the end of the list
• getAt(index) - gets element by index from the list
• getFirst() - gets the first element in the list
• getLast() - gets the last element in the list
• toArray() - returns the values from the list as an array
• contains(element) - checks if a given element exists in the list
• size() - returns the number of elements in the list
• removeAt(index) - removes an element at a given index from the list
• removeFirst() - removes the first element in the list
• removeLast() - removes the last element in the list
• clear() - removes all of the elements from the list

Queue

• add(element) - adds an element to the queue
• poll() - retrieves and removes an element from the beginning of the queue
• peek() - returns an element from the beginning of the queue without removing it
• size() - returns the number of elements in the queue
• isEmpty() - checks if the queue contains any elements

Stack

• push(element) - adds an element to the stack
• pop() - retrieves and removes an element from the end of the stack
• peek() - returns an element from the beginning of the queue without removing it
• search(element) - returns the 1-based position where an element is on the stack
• isEmpty() - checks if the queue contains any elements
• toArray() - returns the values from the stack as an array

Set

• add(element) - adds an element to the set if it isn't already present
• remove(element) - removes an element from the set if it's present
• contains(element) - checks if a given element exists in the set
• size() - returns the number of elements in the set
• isEmpty() - checks if the set contains any elements
• clear() - removes all of the elements from the set
• toArray() - returns the values from the set as an array

HashMap

• put(key, value) - associates the value with the key in the map. If the map previously contained a mapping for the key, the old value is replaced
• get(key) - returns the value to which the specified key is mapped
• remove(key) - removes the mapping for the specified key from the map
• containsKey(key) - checks if the map contains a mapping for the specified key
• size() - returns the number of the mappings in the map
• isEmpty() - checks if the map contains any key-value mappings
• keySet() - retrieves all of the keys contained in the map
• values() - retrieves all of the values contained in the map
• entrySet() - retrieves the mappings contained in the map
• clear() - removes all of the mappings from the map

BinaryTree

• breadthFirstSearch() - traverses the tree using the Breadth First Search algorithm
• depthFirstSearch() - traverses the tree using the Depth First Search algorithm