The removeAll() method of SortedSet interface is used to remove from this SortedSet all of its elements that are contained in the specified collection.
Syntax:
public boolean removeAll(Collection c)
Parameters: This method takes collection c as a parameter containing elements to be removed from this SortedSet.
Returns Value: This method returns true if this set changed as a result of the call.
Exception: This method throws NullPointerException if this set contains a null element and the specified collection does not permit null elements (optional), or if the specified collection is null.
Note: The removeAll() method in SortedSet is inherited from the Set interface in Java.
Below are the examples to illustrate the removeAll() method.
Example 1:
Java
// Java program to demonstrate // removeAll() method for Integer value import java.util.*; public class GFG1 { public static void main(String[] args) throws Exception { try { // Creating object of SortedSet SortedSet<Integer> set1 = new TreeSet<Integer>(); // Populating set1 set1.add( 1 ); set1.add( 2 ); set1.add( 3 ); set1.add( 4 ); set1.add( 5 ); // print set1 System.out.println( "Set before " + "removeAll() operation : " + set1); // Creating another object of Set SortedSet<Integer> set2 = new TreeSet<Integer>(); set2.add( 1 ); set2.add( 2 ); set2.add( 3 ); // print set2 System.out.println( "Collection Elements " + "to be removed : " + set2); // Removing elements from set // specified in set2 // using removeAll() method set1.removeAll(set2); // print set1 System.out.println( "Set after " + "removeAll() operation : " + set1); } catch (NullPointerException e) { System.out.println("Exception thrown : " + e); } } } |
Set before removeAll() operation : [1, 2, 3, 4, 5] Collection Elements to be removed : [1, 2, 3] Set after removeAll() operation : [4, 5]
Example 2: For NullPointerException.
Java
// Java program to demonstrate // removeAll() method for Integer value import java.util.*; public class GFG1 { public static void main(String[] args) throws Exception { try { // Creating object of SortedSet SortedSet<Integer> set1 = new TreeSet<Integer>(); // Populating set1 set1.add( 1 ); set1.add( 2 ); set1.add( 3 ); set1.add( 4 ); set1.add( 5 ); // print set1 System.out.println( "Set before " + "removeAll() operation : " + set1); // Creating another object of SortedSet<Integer> SortedSet<Integer> set2 = null ; // print set2 System.out.println( "Collection Elements" + " to be removed : " + set2); System.out.println( "\nTrying to pass " + " null as a specified element\n"); // Removing elements from set // specified in set2 // using removeAll() method set1.removeAll(set2); // print set1 System.out.println( "Set after " + "removeAll() operation : " + set1); } catch (NullPointerException e) { System.out.println(e); } } } |
Set before removeAll() operation : [1, 2, 3, 4, 5] Collection Elements to be removed : null Trying to pass null as a specified element java.lang.NullPointerException
Reference: https://docs.oracle.com/javase/7/docs/api/java/util/Set.html#removeAll(java.util.Collection)