Properties setProperty(String, String) in Java

setProperty(String, String): This method is available in java.util.Properties class of Java.

Syntax:

Object java.util.Properties.setProperty(String key, String value)

This method takes two arguments. This method calls the Hashtable method put.

Parameters: Two parameters are required for this method.

key: the key to be placed into this property list.

value: the value corresponding to the key.

Returns: the previous value of the specified key in this property list, or null if it did not have one.

Exceptions: NA

Approach

Java

import java.util.Properties;

public class PropertiessetProperty {
    public static void main(String[] args) {

        Properties properties = new Properties();

        properties.put("Hello", "World");
        properties.put("C++", "Program");
        properties.put("Java", "Program");

        String key = "Joy", value = "Enjoy";

        System.out.println(properties.setProperty(key, value));
    }
}

Output:

null