AP CSA Unit 2 Vocabulary

DRY Principle

a software development principle that stands for "Don't Repeat Yourself" which aims to reduce repetition in code

access modifier

a keyword used to set the visibility of classes, variables, constructors, and methods

encapsulation

an object-oriented programming concept where the instance variables of a class are hidden from other classes and can be accessed only through the methods of the class

instance variable

a variable defined in a class that represents an attribute of an object

refactor

to improve the readability, reusability, or structure of program code without altering its functionality

constructor signature

the first line of the constructor which includes the public keyword, the constructor name, and any parameters

default value

a predefined value that is used by a program when the user does not provide a value

no-argument constructor

a constructor with no parameters

actual parameter

the value to assign to the formal parameter

call by value

copying the value of the actual parameter to the constructor's formal parameter

formal parameter

the value to be passed to a constructor or method

local variable

a variable declared and accessible within a specific block of code

overloading

defining two or more constructors or methods with the same name but different signatures

parameterized constructor

a constructor that has a specific number of arguments to be passed to assign values to an object's instance variables

state

the attributes of an object that are represented by its instance variables

scope

where a variable can be used

assignment

using the assignment operator to initialize or change the value stored in a variable

initialization

giving a starting value to a variable using the assignment operator

literal

a source code representation of a value, such as a number or text

primitive type

a basic data type that Java predefines

reference type

a data type that contains a pointer to the memory location of an object

accessor method

gives the value that is currently assigned to an instance variable

application program interface (API)

a library of prewritten classes

library

a collection of methods or reusable components of code

return by value

a copy of the value is given to where the method is called

compound assignment operator

shortcut syntax to perform an operation on both operands and assign the result into the variable on the left

compound expression

a combination of expressions

concatenation

when two strings are joined together

expression

a combination of data and operators that evaluates to a single value

operand

the data that is operated on

truncate

to cut off data from the end

Boolean expression

a logical statement that gives either a true or false value

mutator method

changes the value assigned to an instance variable

relational operator

an operator used to compare values or expressions

escape sequence

starts with a \ to indicate how to display a string

override

to define a method in a subclass with the same method signature as a method inherited from a superclass