Question

What are parameters for? What is the difference between formal parameters and actual parameters? Give an example in Java code that illustrates formal parameters and actual parameters.

Answer 1

Parameters are used to provide some external data for a method. A formal parameter is a variable in a function definition, while an actual parameter is an actual input at function call.

The next Java code illustrates formal and actual parameters:

class Main
{
    // The parameter in the function definition is a formal one
    public static void method(int formalParameter) { }

    public static void main(String[] args)
    {
        // The next variable that is passed to the method is an actual parameter
        int actualParameter = 5;
        method(actualParameter);
    }
}

See more here:

https://en.wikipedia.org/wiki/Parameter_(computer_programming)#Parameters_and_arguments