﻿ Java: Get a key-value mapping of greatest key in a map

# Java Collection, TreeMap Exercises: Remove and get a key-value mapping associated with the greatest key in this map

## Java Collection, TreeMap Exercises: Exercise-20 with Solution

Write a Java program to remove and get a key-value mapping associated with the greatest key in this map.

Sample Solution:-

Java Code:

``````import java.util.*;
import java.util.Map.Entry;
public class Example20 {
public static void main(String args[]) {

// Create a tree map
TreeMap < Integer, String > tree_map = new TreeMap < Integer, String > ();

// Put elements to the map
tree_map.put(10, "Red");
tree_map.put(20, "Green");
tree_map.put(40, "Black");
tree_map.put(50, "White");
tree_map.put(60, "Pink");

// polling first entry
System.out.println("Value before poll: " + tree_map);
System.out.println("Value returned: " + tree_map.pollLastEntry());
System.out.println("Value after poll: " + tree_map);
}
}
``````

Sample Output:

```Value before poll: {10=Red, 20=Green, 40=Black, 50=White, 60=Pink}
Value returned: 60=Pink
Value after poll: {10=Red, 20=Green, 40=Black, 50=White} ```

Java Code Editor:

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## Java: Tips of the Day

getEnumMap

Converts to enum to Map where key is the name and value is Enum itself.

```public static <E extends Enum<E>> Map<String, E> getEnumMap(final Class<E> enumClass) {
return Arrays.stream(enumClass.getEnumConstants())
.collect(Collectors.toMap(Enum::name, Function.identity()));
}
```

Ref: https://bit.ly/3xXcFZt