﻿ Java: Portion of a map, keys are greater or equal to a key

# Java Collection, TreeMap Exercises: Get a portion of a map whose keys are greater than or equal to a given key

## Java Collection, TreeMap Exercises: Exercise-23 with Solution

Write a Java program to get a portion of a map whose keys are greater than or equal to a given key.

Sample Solution:-

Java Code:

``````import java.util.*;
import java.util.Map.Entry;
public class Example23 {
public static void main(String args[]) {

// Declare tree maps
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(30, "Black");
tree_map.put(40, "White");
tree_map.put(50, "Pink");
System.out.println("Orginal TreeMap content: " + tree_map);
System.out.println("Keys are greater than or equal to 20: " + tree_map.tailMap(20));
}
}
``````

Sample Output:

```Orginal TreeMap content: {10=Red, 20=Green, 30=Black, 40=White, 50=Pink
}
Keys are greater than or equal to 20: {20=Green, 30=Black, 40=White, 50
=Pink}```

Java Code Editor:

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.

﻿

## 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