TreeMap class Methods in Java Part -I

java.util.TreeMap

A Red-Black tree-based NavigableMap implementation. The map is sorted according to the natural ordering of its keys, or by a Comparator provided at map creation time, depending on which constructor is used.

Some methods of TreeMap class

ceilingEntry(Integer): This method returns a key-value mapping associated with the least key greater than or equal to the given key, or null if there is no such key.

ceilingKey(Integer): This method returns the least key greater than or equal to the given key, or null if there is no such key.

clear(): This method removes all of the mappings from this map.

clone(): This method returns a shallow copy of this TreeMap instance. 

comparator(): This method returns the comparator used to order the keys in this map, or null if this map uses the natural ordering of its keys.

compute(K, BiFunction): This method attempts to compute a mapping for the specified key and its current mapped value (or null if there is no current mapping).

computeIfAbsent(K, Function): If the specified key is not already associated with a value (or is mapped to null), attempt to compute its value using the given mapping function and enter it into this map unless null.

computeIfPresent(K, BiFunction): If the value for the specified key is present and non-null, attempts to compute a new mapping given the key and its current mapped value.

containsKey(Object): This method returns true if this map contains a mapping for the specified key.

containsValue(Object): This method returns true if this map maps one or more keys to the specified value.

descendingKeySet(): This method returns a reverse order NavigableSet view of the keys contained in this map.

descendingMap(): This method returns a reverse order view of the mappings contained in this map.

entrySet(): This method returns a Set view of the mappings contained in this map.

firstEntry(): This method returns a key-value mapping associated with the least key in this map, or null if the map is empty.

firstKey(): This method returns the first (lowest) key currently on this map.

Some more Methods of TreeMap class Part-II

Some more Methods of TreeMap class Part-III