Ace the AP Computer Science Exam for High Schoolers/

...

/

Different Classifications of Methods

Different Classifications of Methods

Let's take a look at the different ways to classify methods in Java.

We'll cover the following...

Void method vs. non-void method

As we discussed in the last lesson, a method may or may not return a value.

  • A void method is a method that does not return anything. It is declared using the keyword void.

  • A method that returns a value can be classified as a non-void method. The return type for such functions can be primitive or reference type.

Java
class VoidVsNonVoid 
{
    // A void method has a 'void' return type
    public static void greet(String name)
    {
        System.out.format("Happy reading %s!%n", name);
        return;
    }
    // A non-void method can have any primitive or reference data type as its return type
    public static int addFive(int number)
    {
        return number + 5;  // a void method uses 'return' keyword at the conclusion to return an output
    }
    public static void main(String args[]) 
    {
        // calling a void method
        greet("Frodo");
        // calling a non-void method, value returned by function is stored in 'num'
        int num = addFive(10);
        System.out.println(num);
    }
}

  • A void method may or may not use the return keyword (lines 4-8). Even if it uses it, it cannot return anything, so it is not followed by any expression. When calling a void method (line 19 ...