Illustrate with example the use of valueOf() method.

The valueOf() method is a built-in method in Java that is used to return the object representation of the arguments passed. It is available in all wrapper classes like Integer, Long, Boolean, etc.

Here is an example of how to use the valueOf() method in Java:

public class Main {
    public static void main(String[] args) {
        // Here we are using valueOf() method with Integer wrapper class
        Integer myInt = Integer.valueOf(10);
        System.out.println(myInt);  // prints: 10

        // Here we are using valueOf() method with Boolean wrapper class
        Boolean myBool = Boolean.valueOf(true);
        System.out.println(myBool);  // prints: true

        // Here we are using valueOf() method with String. It returns the integer value of the string if string can be parsed to integer.
        Integer myIntFromString = Integer.valueOf("123");
        System.out.println(myIntFromString);  // prints: 123
    }
}

In this example, we used the valueOf() method with the Integer and Boolean wrapper classes to convert an int and a boolean to an Integer and a Boolean object, respectively. We also used it to convert a String to an Integer. If the string cannot be parsed to an integer, it will throw a NumberFormatException.