The contains(value) method of Properties class is used to check if this Properties object contains any mapping of this value for any key present in it. It takes this value to be compared as a parameter and returns a boolean value as a result. This method is more expensive than the containsKey() method. Also, this method is the same in working as the containsValue() method.
Syntax:
public Object contains(Object value)
Parameters: This method accepts a parameter value which is the value to be searched in this Properties.
Returns: This method returns a boolean value stating the result whether this value is present in this Properties object or not.
Below programs illustrate the contains(value) method:
Program 1:
// Java program to demonstrate// contains(value) 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("Current Properties: "                           + properties.toString());          // Check if 10 is present or not        // using contains()        System.out.println("Is 10 present: "                           + properties.contains(10));    }} |
Current Properties: {Book=500, Mobile=5000, Pen=10, Clothes=400}
Is 10 present: true
Program 2:
// Java program to demonstrate// contains(value) 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(1, "100RS");        properties.put(2, "500RS");        properties.put(3, "1000RS");          // print Properties details        System.out.println("Current Properties: "                           + properties.toString());          // Check if 200RS is present or not        // using contains()        System.out.println("Is 200RS present: "                           + properties.contains("200RS"));    }} |
Current Properties: {3=1000RS, 2=500RS, 1=100RS}
Is 200RS present: false
References: https://docs.oracle.com/javase/9/docs/api/java/util/Properties.html#contains-java.lang.Object-
