hashset remove in java code example
Example 1: HashSet remove(Object o) method in java
import java.util.HashSet;
public class HashSetRemoveObjectMethodExample
{
public static void main(String[] args)
{
HashSet<String> hs = new HashSet<String>();
hs.add("hello");
hs.add("world");
hs.add("java");
System.out.println("HashSet before using remove(Object o) method: " + hs);
boolean bool = hs.remove("world");
System.out.println("Has string removed? " + bool);
System.out.println("HashSet after using remove(Object o) method: " + hs);
}
}
Example 2: HashSet removeAll() method in java
import java.util.HashSet;
public class HashSetRemoveAllMethodExample
{
public static void main(String[] args)
{
try
{
HashSet<Integer> hs1 = new HashSet<Integer>();
hs1.add(2);
hs1.add(4);
hs1.add(6);
hs1.add(8);
hs1.add(10);
System.out.println("HashSet before using removeAll() method: " + hs1);
HashSet<Integer> hs2 = new HashSet<Integer>();
hs2.add(2);
hs2.add(4);
hs2.add(6);
System.out.println("Elements to be removed: " + hs2);
hs1.removeAll(hs2);
System.out.println("HashSet after using removeAll() method: " + hs1);
}
catch(NullPointerException ex)
{
System.out.println("Exception: " + ex);
}
}
}