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🏗️AP Computer Science A Unit 3 Vocabulary

74 essential vocabulary terms and definitions for Unit 3 – Class Creation

Study Unit 3
Practice Vocabulary
🏗️Unit 3 – Class Creation
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🏗️Unit 3 – Class Creation

TermDefinition
enclosing classThe class in which a method is defined.
mutable objectAn object whose state can be changed after it is created; when used as a constructor parameter, a copy should be made to prevent external modification.
object referenceA value that points to the memory location where an object is stored, allowing access to that object.
parameterA variable declared in the header of a method or constructor that receives values passed to the method when it is called.
private dataClass members declared with the private access modifier that can only be accessed within the same class.
return expressionThe value or reference that a method sends back to the code that called it.

TermDefinition
access constraintsRestrictions that control which classes and methods can access or modify a class, data, constructors, or methods.
attributeThe data or properties that define the state of an object or class.
behaviorThe methods or actions that an object or class can perform.
constructorsSpecial methods used to initialize objects of a class, typically designated as public in this course.
data encapsulationA technique in which the implementation details of a class are kept hidden from external classes to protect internal structure and behavior.
instance variableA variable that belongs to an object and can be accessed throughout the class, as opposed to a local variable that is limited to a specific block of code.
methodA named block of code that only runs when it is called, allowing programmers to reuse code and organize programs into logical sections.
privateA keyword that restricts access to a class, data, constructor, or method to only the declaring class.
publicA keyword that allows access to a class, data, constructor, or method from classes outside the declaring class.
visibility constraintsSpecifications that determine whether classes, data, constructors, and methods are visible and accessible to external classes.

TermDefinition
abstractionThe process of reducing complexity by focusing on main ideas and hiding irrelevant details while bringing together related and useful details.
attributeThe data or properties that define the state of an object or class.
classA formal implementation or blueprint that defines the attributes and behaviors of objects.
class variableVariables that belong to the class itself rather than individual objects and can be accessed or modified by accessor and mutator methods.
code reuseThe practice of using existing methods and procedural abstractions multiple times rather than duplicating code, which helps manage complexity.
data abstractionA separation between the abstract properties of a data type and the concrete details of its representation, allowing data to be named without referencing specific implementation details.
instance variableA variable that belongs to an object and can be accessed throughout the class, as opposed to a local variable that is limited to a specific block of code.
methodA named block of code that only runs when it is called, allowing programmers to reuse code and organize programs into logical sections.
method decompositionThe process of breaking down larger behaviors of a class into smaller behaviors by creating individual methods to represent each smaller behavior.
method signatureThe combination of a method's name and its ordered list of parameter types, used to identify and call a specific method.
parametersVariables that allow procedures to be generalized and reused with a range of input values or arguments.
procedural abstractionThe ability to use a method by knowing what it does without needing to understand how it was implemented.

TermDefinition
accessor methodA non-void method that allows objects of other classes to obtain a copy of the value of instance variables or class variables.
class variableVariables that belong to the class itself rather than individual objects and can be accessed or modified by accessor and mutator methods.
instance variableA variable that belongs to an object and can be accessed throughout the class, as opposed to a local variable that is limited to a specific block of code.
mutator methodA method that changes the values of instance variables or class variables, often implemented as a void method.
non-void methodA method that returns a value of a specified type that can be stored in a variable or used as part of an expression.
parametersVariables that allow procedures to be generalized and reused with a range of input values or arguments.
primitive valuesBasic data types in Java such as int, double, and boolean that store actual values directly.
return by valueThe process in which a non-void method evaluates a return expression compatible with the return type and returns that value.
return statementA statement that terminates method execution and returns control flow to the point immediately following where the method was called.
return typeThe data type of the value that a non-void method returns, specified in the method header.
void methodA method that does not return a value and cannot be used as part of an expression.

TermDefinition
class methodA method that belongs to the class itself rather than to individual instances and does not have access to a this reference.
constructorA special method that is called to create and initialize an object of a class, having the same name as the class.
current objectThe specific object instance whose method or constructor is being executed.
instance methodA method that belongs to an object instance and can access and modify the instance's data through the this keyword.
method callAn invocation of a method that interrupts sequential execution and causes the program to execute the method's statements before returning control to the calling location.
self-referencingCode that refers to the current object using the this keyword.
this keywordA special variable that holds a reference to the current object within an instance method or constructor.

TermDefinition
attributeThe data or properties that define the state of an object or class.
constructorA special method that is called to create and initialize an object of a class, having the same name as the class.
constructor parametersData passed to a constructor that is used to initialize instance variables with specific values.
default constructorA no-parameter constructor automatically provided by Java when no constructor is explicitly written; initializes instance variables to default values.
default valuesThe initial values automatically assigned to instance variables by the default constructor based on their data type (0 for int, 0.0 for double, false for boolean, null for reference types).
has-a relationshipA relationship between an object and its instance variables, indicating that an object has certain attributes.
instance variableA variable that belongs to an object and can be accessed throughout the class, as opposed to a local variable that is limited to a specific block of code.
mutable objectAn object whose state can be changed after it is created; when used as a constructor parameter, a copy should be made to prevent external modification.
object's stateThe current values of all instance variables belonging to an object at a given time.

TermDefinition
class methodsMethods that are associated with a class rather than with instances of the class, and include the static keyword in their header.
class variableVariables that belong to the class itself rather than individual objects and can be accessed or modified by accessor and mutator methods.
dot operatorThe symbol (.) used in Java to access instance methods and properties of an object.
final keywordA Java keyword that, when applied to a variable, prevents its value from being modified after initialization.
instance methodsMethods that belong to an object and are called on specific instances of a class using the dot operator.
instance variableA variable that belongs to an object and can be accessed throughout the class, as opposed to a local variable that is limited to a specific block of code.
parameterA variable declared in the header of a method or constructor that receives values passed to the method when it is called.
public access modifierA keyword that allows class variables to be accessed outside of the class using the class name and dot operator.
static keywordA Java keyword used to designate that a variable belongs to the class rather than to individual objects of the class.

TermDefinition
block of codeA section of code enclosed in braces that defines a region where variables can be declared and accessed.
instance variableA variable that belongs to an object and can be accessed throughout the class, as opposed to a local variable that is limited to a specific block of code.
local variablesVariables declared in the headers or bodies of blocks of code that can only be accessed within the block in which they are declared.
parametersVariables that allow procedures to be generalized and reused with a range of input values or arguments.
scopeThe region of code in which a variable can be accessed and used.

TermDefinition
ethical implicationsThe moral and ethical consequences of computing systems, including questions about right and wrong in their design and use.
intellectual propertyLegal rights and protections for original creative works, including software code and programs.
open sourceSoftware code that is publicly available and free to use, modify, and distribute without requiring permission or payment.
social implicationsThe effects and consequences of computing systems on society, including how they impact people's lives and social structures.
system reliabilityThe ability of a program to perform its intended tasks as expected under stated conditions without failure.