When we are working with ArrayList of Objects then it is must that we have to override toString() method of Java ArrayList to get the output in the desired format. Lets learn how to override toString() method. [Read more…]
Find Common Elements between two ArrayList in Java
In this tutorial we will learn how to get the common elements between two ArrayList. We would be using removeAll() method to retain only the common elements between two lists.
public boolean removeAll(Collection<?> c)
It removes all the elements in the list that are not contained in the specified list. [Read more…]
Java TreeMap values() Method Example
The values() method of java.util.TreeMap class returns a Collection view of the values contained in this map. The collection’s iterator returns the values in ascending order of the corresponding keys.
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Java TreeMap subMap(K fromKey,K toKey) Method Example
The subMap(K fromKey, K toKey) method of java.util.TreeMap class returns a view of the portion of this map whose keys range from fromKey, inclusive, to toKey, exclusive. The returned map is backed by this map, so changes in the returned map are reflected in this map, and vice-versa. The returned map supports all optional map operations that this map supports.
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Java TreeMap size() Method Example
The size() method of java.util.TreeMap class returns the number of key-value mappings in this map.
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Java TreeMap remove(Object key) Method Example
The remove(Object key) method of java.util.TreeMap class removes the mapping for this key from this TreeMap if present.
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Java TreeMap pollLastEntry() Method Example
The pollFirstEntry() method of java.util.TreeMap class removes and returns a key-value mapping associated with the least key in this map, or null if the map is empty where as pollLastEntry() method removes and returns a key-value mapping associated with the greatest key in this map, or null if the map is empty.
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Java TreeMap pollFirstEntry() Method Example
The pollFirstEntry() method of java.util.TreeMap class removes and returns a key-value mapping associated with the least key in this map, or null if the map is empty.
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Java TreeMap navigableKeySet() Method Example
The descendingKeySet() method of java.util.TreeMap class returns a reverse order NavigableSet view of the keys contained in this map. The set’s iterator returns the keys in descending order whereas navigableKeySet() returns a NavigableSet view of the keys contained in this map. The set’s iterator returns the keys in ascending order. The set is backed by the map, so changes to the map are reflected in the set, and vice-versa.
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Java TreeMap lowerKey(K key) Method Example
The lowerEntry(K key) method of java.util.TreeMap class returns a key-value mapping associated with the greatest key strictly less than the given key, or null if there is no such key. whereas lowerKey(K key) method returns the greatest key strictly less than the given key, or null if there is no such key.
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