CSA Java PLTW Review

syntax

Precise rules defining how the letters, words, and punctuation of a programming language are required to be used

class

blueprint, of the attributes and behaviors of an object. It is an abstraction defining a type of object, with methods and attributes

object

specific instance of a class with defined attributes

method

Methods define an object's behavior, what it can do, or what can be done to it.

main method

main entry point of the program, with header: public static void main(String[] args)

string

A data type representing a sequence of characters.

primitive variables

int - integer (whole numbers: 0, 1, 2, 3)

double - real values (0.0, 3.145, -2.72)

char - single character values ('a' , '3' , '$')

boolean - only one of two values: true or false

what must be defined to create a variable

the type, identifier, and value

Camel Casing

A style of creating identifiers in which the first letter is not capitalized, but each new word is.

modulus operator

finds the remainder after division of one number by another.

comment

lines ignored by compiler to describe function of code

arithmetic operators

+,-,*,/,%

concatination

Attaching two things side-by-side, frequently strings of text.

concatenation operator

+ (plus sign)

compound assignment operator

performs two tasks in one step; it performs a mathematical calculation followed by an assignment.

increment and decrement operators

++, --, increase or decrease value by 1

machine code

Zeros and ones that represent simple instructions executed by a processor.

overflow

occurs when an integer value falls outside of the allowed range

widening

process by which a value is converted from a smaller data type (such as an int) to a larger data type (such as a double)

narrowing

process by which a value is converted from a larger data type (such as a double) to a smaller data type (such as an integer).

type casting

converting from one data type to another temporarily

casting operators

used to case data types, (int) or (double)

object-oriented programming(oop)

programming in which code describes a class with methods, including a method for creating an object

instantiation

process of creating an object

constructor

method for creating an object in a class.

signature

defines a constructor or a method. It is the name and a list of parameters, such as "Cake(int t)"

header

has access level(public or private), return type(void, int, ect.), signature(name and paramaters)

formal paramaters

list of variables passed to a constructor or method and used in its implementation

package

collection of modules

overloading

multiple definitions with the same name but different signatures.

actual paramaters

value that is passed into a constructor or method

Call by value

constructors or methods are called, call by value initializes formal parameters with copies of the actual parameters

object reference variables

hold a memory address that refers to a specific object

dot operator

the period or dot (.) is used to invoke an object's method

non-static

type of method call. It means that an object must be instantiated to invoke the method

abstraction

hiding a lot of the detail of a system or a process, making it simpler to read and understand

null

no value

exception

error or other message raised by the interpreter or compiler to indicate a special circumstance that should be handled by an exception handler. If an exception is not handled, the program will stop and report the error

scope of a variable

defines where it is accessible or visible in a program