Title: Pass and return objects/primitive parameters to methods.
Course: Java Programming (Oracle) (10055) > Section: Understanding Methods and Classes

Passing objects or primitives involves the recognition of the method signature that is located immediately after the method name in parentheses. In the parentheses, the type of primitive/object required by the code to execute is followed by a name given to the primitive or object. In order to pass a parameter, the appropriate object or primitive must be placed in the parenthesis when the method is called.

The general format for the calling of an object is as follows:

objectName.methodName(required object/primitive);

Returning an object or primitive from a method requires that the method be defined with the keyword return. Once the method is called, the returned object must be assigned to a space in memory either declared at the time the method was called or previously declared in the program. When a method returns a value, it must return it into a container of the appropriate type. If a method returns an integer, there must be a variable of type integer waiting to receive it. Sample code follows:

String number = new String("2");
int a;
a = Integer.parseInt(number);

In this example, the variable number is the required parameter as defined in the API. The Integer.parseInt
method's signature asks for a string and returns an int representation of that string to the assignment operator.