Write a Java program to Remove elements from HashSet collection based on a specified predicate
The program starts with the import statement import java.util.*;, which imports all classes from the java.util package, including HashSet.
- The program defines a class called RemoveEle_HashSet. Inside the RemoveEle_HashSet class, the main method is declared and serves as the entry point for the program. It takes an array of strings (args) as input.
- Within the main method, a HashSet called nums is created and initialized with Integer objects. The HashSet represents a set of numbers.
- After initializing nums with some elements using the add() method, the program proceeds to demonstrate the usage of the removeIf() method.
- The removeIf() method is called on the nums HashSet and takes a lambda expression as an argument. The lambda expression (val -> (val > 5)) represents a predicate that returns true if the value is greater than 5.
- The removeIf() method removes all elements from the HashSet that satisfy the given predicate. In this case, all elements greater than 5 will be removed.
- If any elements are removed, the program prints "Items removed successfully." Otherwise, it prints "Unable to remove Items."
- Finally, the program prints the updated elements of the HashSet using the System.out.println() statement.
Source Code
import java.util.*;
public class RemoveEle_HashSet
{
public static void main(String[] args)
{
HashSet <Integer> nums = new HashSet<Integer>();
nums.add(1);
nums.add(2);
nums.add(3);
nums.add(4);
nums.add(5);
nums.add(6);
nums.add(7);
nums.add(8);
nums.add(9);
nums.add(10);
System.out.println("HashSet Elements : " + nums);
if (nums.removeIf(val -> (val > 5)))
{
System.out.println("Items removed successfully.");
}
else
{
System.out.println("Unable to remove Items.");
}
System.out.println("HashSet Elements : " + nums);
}
}
Output
HashSet Elements : [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
Items removed successfully.
HashSet Elements : [1, 2, 3, 4, 5]