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Found 9313 Articles for Object Oriented Programming
![karthikeya Boyini](https://www.tutorialspoint.com/assets/profiles/13518/profile/60_31598-1537784993.jpg)
113 Views
To display the last key from NavigableMap in Java, use the lastKey() method.Let us first create NavigableMap −NavigableMap n = new TreeMap(); n.put("A", 498); n.put("B", 389); n.put("C", 868); n.put("D", 988); n.put("E", 686); n.put("F", 888); n.put("G", 999); n.put("H", 444); n.put("I", 555); n.put("J", 666);Get the last key now −n.lastKey()The following is an example to get the last key from NavigableMap.Example Live Demoimport java.util.*; public class Demo { public static void main(String[] args) { NavigableMap n = new TreeMap(); n.put("A", 498); n.put("B", 389); ... Read More
![Samual Sam](https://www.tutorialspoint.com/assets/profiles/13514/profile/60_83486-1512649303.jpg)
111 Views
To display first entry from NavigableMap in Java, use the firstEntry() method.Let us first create NavigableMap −NavigableMap n = new TreeMap(); n.put("A", 498); n.put("B", 389); n.put("C", 868); n.put("D", 988); n.put("E", 686); n.put("F", 888); n.put("G", 999); n.put("H", 444); n.put("I", 555); n.put("J", 666);Get the first entry now −n.firstEntry()The following is an example to get first entry from NavigableMap.Example Live Demoimport java.util.*; public class Demo { public static void main(String[] args) { NavigableMap n = new TreeMap(); n.put("A", 498); n.put("B", 389); ... Read More
![karthikeya Boyini](https://www.tutorialspoint.com/assets/profiles/13518/profile/60_31598-1537784993.jpg)
132 Views
To display the first key from NavigableMap in Java, use the firstKey() method.Let us first create NavigableMap −NavigableMap n = new TreeMap(); n.put("A", 498); n.put("B", 389); n.put("C", 868); n.put("D", 988); n.put("E", 686); n.put("F", 888); n.put("G", 999); n.put("H", 444); n.put("I", 555); n.put("J", 666);Get the first key now −n.firstKey()The following is an example to get the first key from NavigableMap −Example Live Demoimport java.util.*; public class Demo { public static void main(String[] args) { NavigableMap n = new TreeMap(); n.put("A", 498); n.put("B", ... Read More
![Samual Sam](https://www.tutorialspoint.com/assets/profiles/13514/profile/60_83486-1512649303.jpg)
891 Views
To remove the first entry of the TreeMap, use the pollFirstEntry() method.Let us first create a TreeMap and add elements −TreeMap m = new TreeMap(); m.put(1, "India"); m.put(2, "US"); m.put(3, "Australia"); m.put(4, "Netherlands"); m.put(5, "Canada");Remove the first entry now −m.pollFirstEntry()The following is an example to remove the first entry of the TreeMap.Example Live Demoimport java.util.*; public class Demo { public static void main(String args[]) { TreeMap m = new TreeMap(); m.put(1, "India"); m.put(2, "US"); ... Read More
![karthikeya Boyini](https://www.tutorialspoint.com/assets/profiles/13518/profile/60_31598-1537784993.jpg)
96 Views
Use the remove() method to remove a key from a TreeMap only if it is associated with a given value. Let us first create a TreeMap and add some elements −TreeMap m = new TreeMap(); m.put(1, "India"); m.put(2, "US"); m.put(3, "Australia"); m.put(4, "Netherlands"); m.put(5, "Canada");To remove a key, set the key and the associated value here. If the associate value exists, then the key will get removed −m.remove(3, "Australia")The following is an example to remove a key from a TreeMap only if it is associated with a given value −Example Live Demoimport java.util.*; public class Demo { public static void ... Read More
![Samual Sam](https://www.tutorialspoint.com/assets/profiles/13514/profile/60_83486-1512649303.jpg)
457 Views
Use the remove() method to remove a key from TreeMap.Let us first create a TreeMap and add some elements −TreeMap m = new TreeMap(); m.put(1, "India"); m.put(2, "US"); m.put(3, "Australia"); m.put(4, "Netherlands"); m.put(5, "Canada");Let us remove a key now. Here, we are removing key 3 now −m.remove(3)The following is an example to remove a key from TreeMap −Example Live Demoimport java.util.*; public class Demo { public static void main(String args[]) { TreeMap m = new TreeMap(); m.put(1, "India"); m.put(2, "US"); m.put(3, "Australia"); m.put(4, "Netherlands"); ... Read More
![karthikeya Boyini](https://www.tutorialspoint.com/assets/profiles/13518/profile/60_31598-1537784993.jpg)
1K+ Views
A TreeMap cannot contain duplicate keys. TreeMap cannot contain the null key. However, It can have null values.Let us first see how to create a TreeMap −TreeMap m = new TreeMap();Add some elements in the form of key-value pairs −m.put(1, "India"); m.put(2, "US"); m.put(3, "Australia"); m.put(4, "Netherlands"); m.put(5, "Canada");The following is an example to create a TreeMap and add key-value pairs −Example Live Demoimport java.util.*; public class Demo { public static void main(String args[]) { TreeMap m = new TreeMap(); m.put(1, "India"); m.put(2, "US"); m.put(3, "Australia"); ... Read More
![Samual Sam](https://www.tutorialspoint.com/assets/profiles/13514/profile/60_83486-1512649303.jpg)
650 Views
Use the remove() method to remove a value from TreeMap.Create a TreeMap first and add some elements −TreeMap m = new TreeMap(); m.put(1, "PHP"); m.put(2, "jQuery"); m.put(3, "JavaScript"); m.put(4, "Ruby"); m.put(5, "Java"); m.put(6, "AngularJS"); m.put(7, "ExpressJS");Now, let’s say you need to remove a value with key 5. For that, use the remove() method −Object ob = m.remove(5);The following is an example to remove a value from TreeMap −Example Live Demoimport java.util.*; public class Demo { public static void main(String args[]) { TreeMap m = new TreeMap(); m.put(1, "PHP"); m.put(2, "jQuery"); ... Read More
![karthikeya Boyini](https://www.tutorialspoint.com/assets/profiles/13518/profile/60_31598-1537784993.jpg)
132 Views
Get the TreeMap size using the size() method.First, create a TreeMap and add elements to it −TreeMap m = new TreeMap(); m.put(1, "PHP"); m.put(2, "jQuery"); m.put(3, "JavaScript"); m.put(4, "Ruby"); m.put(5, "Java"); m.put(6, "AngularJS"); m.put(7, "ExpressJS");Count the number of elements in the above TreeMap or get the size using the size() method as shown below −m.size()To get the size of TreeMap, the following is the code −Example Live Demoimport java.util.*; public class Demo { public static void main(String args[]) { TreeMap m = new TreeMap(); m.put(1, "PHP"); m.put(2, "jQuery"); ... Read More
![Samual Sam](https://www.tutorialspoint.com/assets/profiles/13514/profile/60_83486-1512649303.jpg)
1K+ Views
Use the lastKey() method to get the highest key stored in TreeMap.Let us first set the TreeMap and add some elements to it −TreeMap m = new TreeMap(); m.put(1, "PHP"); m.put(2, "jQuery"); m.put(3, "JavaScript"); m.put(4, "Ruby"); m.put(5, "Java"); m.put(6, "AngularJS"); m.put(7, "ExpressJS");Now get the highest key −m.lastKey()The following is an example to get the highest key in TreeMap −Example Live Demoimport java.util.*; public class Demo { public static void main(String args[]) { TreeMap m = new TreeMap(); m.put(1, "PHP"); m.put(2, "jQuery"); m.put(3, "JavaScript"); m.put(4, "Ruby"); ... Read More