The keys() method of Properties class is used to get the enumeration of the keys in this Properties object. This enumeration can be used to traverse and iterate the keys sequentially.
Syntax:
public Enumeration keys()
Parameters: This method accepts no parameters
Returns: This method returns an Enumeration of the keys of this Properties object sequentially.
Below programs show the implementation of int keys() method.
Program 1:
// Java code to show the implementation of // keys() method import java.util.*;
public class GfG {
// Main method
public static void main(String[] args)
{
// Create a properties and add some values
Properties properties = new Properties();
properties.put( "Pen" , 10 );
properties.put( "Book" , 500 );
properties.put( "Clothes" , 400 );
properties.put( "Mobile" , 5000 );
// Print Properties details
System.out.println( "Properties: "
+ properties.toString());
// Creating an empty enumeration to store
Enumeration enu = properties.keys();
System.out.println( "The enumeration of keys are:" );
// Displaying the Enumeration
while (enu.hasMoreElements()) {
System.out.println(enu.nextElement());
}
}
} |
Output:
Properties: {Book=500, Mobile=5000, Pen=10, Clothes=400} The enumeration of keys are: Book Mobile Pen Clothes
Program 2:
// Java program to demonstrate // keys() method. import java.util.*;
public class GFG {
// Main method
public static void main(String[] args)
{
// Create a properties and add some values
Properties properties = new Properties();
// Inserting elements into the properties
properties.put( "Geeks" , 10 );
properties.put( "4" , 15 );
properties.put( "Geeks" , 20 );
properties.put( "Welcomes" , 25 );
properties.put( "You" , 30 );
// Print Properties details
System.out.println( "Current Properties: "
+ properties.toString());
// Creating an empty enumeration to store
Enumeration enu = properties.keys();
System.out.println( "The enumeration of keys are:" );
// Displaying the Enumeration
while (enu.hasMoreElements()) {
System.out.println(enu.nextElement());
}
}
} |
Output:
Current Properties: {You=30, Welcomes=25, 4=15, Geeks=20} The enumeration of keys are: You Welcomes 4 Geeks
References: https://docs.oracle.com/javase/9/docs/api/java/util/Properties.html#keys–