Java Class Terminology

Question 1

Constructor?

Answer 1

Allows a program/driver to create objects from the class (instantiate an object). Parameters() are optional.

Question 2

Accessor? also know as a?

Answer 2

allows a driver/application to see the value of a private data members (variables) that is inside the class. known as: a getter (accessor).

Question 3

Mutator? also known as?

Answer 3

allows a driver/application to alter the data value of a private variable that is within the class. also known as: a setter.

Question 4

helping method? example?

Answer 4

Can be used within just the class by using a private access modifier we can also have a helping method that is used by the driver so that the results of private objects can be returned. example: public float calcTotal() { return (privateVariable + 2ndPrivateVariable); }

Question 5

toString?

Answer 5

written within the class so that a driver can display a certain format pre determined. routinely displays data.

Question 6

UML?

Answer 6

UML = Unified Modeling Language represents a specific class in visual manner. *We never add instance variables that are not in the UML diagram.

Question 7

instantiate?

Answer 7

instantiate: when an object is created. Done within a class. the object inherits generic values from the class it is created in.

Question 8

what are data members called?

Answer 8

data members: same as instantiated variables / fields.

Question 9

what is a Method?

Answer 9

Method: Created within a class. set of instructions that makes an operation occur. (a formula that is contained within a word or object name).

Question 10

what are the 5 parts that make up a method?

Answer 10

parts of method: 1- modifier 2- return type 3- method name 4- method signature 5- parameter

Question 11

what is a method modifier?

Answer 11

method modifier: The access type of either public or private

Question 12

what is a method return type?

Answer 12

method return type: the data type returned= char, int, double, float.

Question 13

what is a method name?

Answer 13

method name: name i choose for the method to be called on later.

Question 14

what is a method signature?

Answer 14

method signature: method name and parameter list combined

Question 15

what is a method parameter?

Answer 15

method parameter: a placeholder.. when a method is invoked(used) a value is passed called the argument.

Question 16

what is it called when a program or driver contains the main() method?

Answer 16

application -uses classes within their programs.

Question 17

is input generated from: drivers, classes or applications

Answer 17

applications only.

Question 18

user defined class?

Answer 18

class that is not part of the java library. was built by a programmer and does not contain input or output.

Question 19

instance data?

Answer 19

non static data that can change values. usually declared at the top of a class.

Question 20

local data items?

Answer 20

data items declared within class methods such as within a constructor, mutator or accessor.

Question 21

describe what overriding is?

Answer 21

when an already defined method is overwritten with data that is custom or slightly different. **often used with toString() to produce custom output.

Question 22

equals method used?

Answer 22

determines if two objects from the same class are the same. is a boolean of true or false and can be defined within a class.

Question 23

how new objects are instantiated inside a driver?

Answer 23

the class name is used before the instantiated object name (new object) so that the constructor within the class can form the instantiated object the correct way. data is entered inside ().

Question 24

what is the format of a mutator?

Answer 24

ObjectName.MutatorMethod (Arguments needed) example: customerName = in.nextLine(); System.out.print(“enter in the name”) ObjectJulie.setName (customerName);

Question 25

what is a shortcut in code for the driver that will use the toString method with an object?

Answer 25

System.out.print(object); ^ is the same as System.out.print(object.toString());

Question 26

Describe how a Method is set up.
visialize the different parts. How is it “built”?

Answer 26