The enumeration() method of java.util.Collections class is used to return an enumeration over the specified collection. This provides interoperability with legacy APIs that require an enumeration as input.
Syntax:
public static Enumeration enumeration(Collection c)
Parameters: This method takes the collection c as a parameter for which an enumeration is to be returned.
Return Value: This method returns an enumeration over the specified collection.
Below are the examples to illustrate the enumeration() method
Example 1:
Java
// Java program to demonstrate // enumeration() method // for String value import java.util.*;
public class GFG1 {
public static void main(String[] argv) throws Exception
{
try {
// creating object of List<String>
List<String> arrlist = new ArrayList<String>();
// Adding element to srclst
arrlist.add( "Ram" );
arrlist.add( "Gopal" );
arrlist.add( "Verma" );
// Print the list
System.out.println( "List: " + arrlist);
// creating object of type Enumeration<String>
Enumeration<String> e = Collections.enumeration(arrlist);
// Print the Enumeration
System.out.println( "\nEnumeration over list: " );
// print the enumeration
while (e.hasMoreElements())
System.out.println( "Value is: " + e.nextElement());
}
catch (IllegalArgumentException e) {
System.out.println( "Exception thrown : " + e);
}
catch (NoSuchElementException e) {
System.out.println( "Exception thrown : " + e);
}
}
} |
Output:
List: [Ram, Gopal, Verma] Enumeration over list: Value is: Ram Value is: Gopal Value is: Verma
Example 2:
Java
// Java program to demonstrate // enumeration() method // for Integer value import java.util.*;
public class GFG1 {
public static void main(String[] argv) throws Exception
{
try {
// creating object of List<Integer>
List<Integer> arrlist = new ArrayList<Integer>();
// Adding element to srclst
arrlist.add( 20 );
arrlist.add( 30 );
arrlist.add( 40 );
// Print the list
System.out.println( "List: " + arrlist);
// creating object of type Enumeration<Integer>
Enumeration<Integer> e = Collections.enumeration(arrlist);
// Print the Enumeration
System.out.println( "\nEnumeration over list: " );
// print the enumeration
while (e.hasMoreElements())
System.out.println( "Value is: " + e.nextElement());
}
catch (IllegalArgumentException e) {
System.out.println( "Exception thrown : " + e);
}
catch (NoSuchElementException e) {
System.out.println( "Exception thrown : " + e);
}
}
} |
Output:
List: [20, 30, 40] Enumeration over list: Value is: 20 Value is: 30 Value is: 40