This is an example of how to use methods in different classes.
Java methods are methods in a class used to perform actions.
They can either be static or public.
Static Methods can be accessed in a class without creating an object.
Below is an example on using a Static Method. I created a class called UsingClassMethods.
public class UsingClassMethods
{
Then I created a static method called testStaticMethod.
static void testStaticMethod()
{
Finally I call the static method testStaticMethod from the main method.
testStaticMethod();
Below is the hole code put together.
public class UsingClassMethods
{
//Since this method is static it can be accessed in this class without creating an object of this class
static void testStaticMethod()
{
System.out.println("This is called from a static method in UsingClassMethods\n");
}
public static void main(String[] args)
{
//This is called from a static method in this class, UsingClassMethods
testStaticMethod();
}
}
For Public Methods you need to create an object of the class to access them. Below is an example of an Object called testClassObject that uses the class UsingClassMethods.
//This creates a new object of this class, UsingClassMethods
UsingClassMethods testClassObject = new UsingClassMethods();
To access methods in an object you need to first write the object’s name with a dot or .
You can also create an object of a class and access it from another class in a different file. Below you can find my user file. This will be the class used to create an object. It contains a String name and two public methods. The first one setUsername to set the value and the following getUsername to retrieve the value.
//This is the User class as its own file
//It consists of a name string and two methods one to set it and one to retrieve it
public class User
{
String name = "";
public void setUsername(String tempName)
{
name = tempName;
System.out.println("The string has been sent to the User class method setUsername\n");
}
public void getUsername()
{
System.out.println("This is from the User class method getUsername and this is the string sent from UsingClassMethods: " + name +"\n");
}
}
Finally this is an example of using the User class as an object.
//Class Methods are used to call methods between different classes
public class UsingClassMethods
{
//This creates an object of the class User called aUser
User aUser = new User();
System.out.println("This creates an object of a class called User\n");
//This is calling the setUsername method from the object called aUser
aUser.setUsername("Greg");
//This calling the getUsername method from the object called aUser
aUser.getUsername();
}
}
A question to ask yourself. What is the difference between using static and public on methods?
Gregory Reed 