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Chapter 4
Procedural Methods
Learning Java through Alice © Daly and Wrigley
Objectives• Identify classes, objects, and methods.• Identify the difference between a procedure method and a
function method.• Differentiate between parameters and arguments.• Write procedure methods with parameters.• Explain the purpose of the Java API.
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Learning Java through Alice © Daly and Wrigley
Procedure Methods
A procedural method is a coordinated sequence of instructions that will be carried out when requested.
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Learning Java through Alice © Daly and Wrigley
Java Programming Interface (API)
http://docs.oracle.com/javase/8/docs/api/
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Learning Java through Alice © Daly and Wrigley
Method Syntax
The syntax for a method is: modifier static returntype methodname ( list of
parameters ) { .... statements to do inside of method }
• Modifiers determine the scope of a method. ▫ public means that the method is available in the current class
(program) and other classes. ▫ private means that you intend to use the variable or method in the
current program. • Return Type
▫ Data type: int, double, float, etc. ▫ No return type: void
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Learning Java through Alice © Daly and Wrigley
Naming Methods• Consists of letters, digits, underscores (_) or $ (no spaces
allowed). • First character can't be a digit. • Cannot be keywords.• Stylistic Rule: all method names begin with a lowercase letter
with all other words beginning with uppercase letter such as displayIt, sumNumbers, etc.
• Method names should be meaningful.
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Learning Java through Alice © Daly and Wrigley
Methods with No Parameters
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Learning Java through Alice © Daly and Wrigley
Methods with No Parameters
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Learning Java through Alice © Daly and Wrigley
Methods with Some Parameters
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Learning Java through Alice © Daly and Wrigley
Methods with Some Parameters
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Learning Java through Alice © Daly and Wrigley
Object Methods
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Learning Java through Alice © Daly and Wrigley
Static Methods
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